Lloyd George Acoustics
PO Box 717
Hillarys WA 6923
T: 9245 3223 F:9300 4199
E: [email protected] W: www.lgacoustics.com.au
Freight Train Noise
Assessments
Reference: 14113026-02 Final.docx
Prepared for:
Freight & Logistics Council
Member Firm of Association of Australian Acoustical Consultants
Report: 14113026-02 Final.docx
Lloyd George Acoustics Pty Ltd
ABN: 79 125 812 544
PO Box 717
Hillarys WA 6923
T: 9300 4188 / 9401 7770
F: 9300 4199
Contacts
Daniel Lloyd
E:
M:
Terry George
Mike Cake
Matt Moyle
[email protected]
[email protected]
[email protected]
[email protected]
0439 032 844
0400 414 197
0438 201 071
0412 611 330
This report has been prepared in accordance with the scope of services described in the contract or
agreement between Lloyd George Acoustics Pty Ltd and the Client. The report relies upon data, surveys,
measurements and results taken at or under the particular times and conditions specified herein. Any
findings, conclusions or recommendations only apply to the aforementioned circumstances and no greater
reliance should be assumed or drawn by the Client. Furthermore, the report has been prepared solely for
use by the Client, and Lloyd George Acoustics Pty Ltd accepts no responsibility for its use by other parties.
Prepared By:
Mike Cake
Position:
Project Director
Verified
Terry George
Date:
14 September 2015
Lloyd George Acoustics
Table of Contents
1
INTRODUCTION _____________________________________________________________ 3
2
CRITERIA __________________________________________________________________ 4
3
NOISE MEASUREMENTS ______________________________________________________ 5
4
ASSESSMENT OF NOISE MEASUREMENTS _______________________________________ 10
5
MAXIMUM VERSUS AVERAGE NOISE LEVEL ______________________________________ 12
6
SPP GUIDELINES APPENDIX A _________________________________________________ 14
7
APPLYING ARCHITECTURAL PACKAGES __________________________________________ 16
8
Sensitivity Analysis _________________________________________________________ 19
8.1 Analysis of Measured Data ___________________________________________________ 19
8.2 Maximum Noise Criteria _____________________________________________________ 19
8.3 Glazing to Floor Ratio _______________________________________________________ 20
8.4 Upper Limit of Packages _____________________________________________________ 21
9
CONCLUSION ______________________________________________________________ 22
List of Tables
Table 2-1 Outdoor Noise Criteria ______________________________________________________ 4
Table 3-1 Noise Logging Results: 25m From Railway ______________________________________ 5
Table 4-1 Noise Logging Results Adjusted to 1 Movement Per Hour: 25m From Railway _________ 10
Table 6-1 Estimated LAeqNight) Noise Levels Provided in SPP Guidelines ________________________ 14
Table 7-1 External Noise Spectra for Freight Trains ______________________________________ 16
Table 7-2 ‘Typical’ Apartment Room Dimensions ________________________________________ 16
Table 7-3 Calculated Internal Noise Levels – Typical Apartment ____________________________ 17
Table 8-1 Calculated Internal Noise Levels – Larger Glazing ________________________________ 21
Table 8-2 Calculated Internal Noise Levels – Typical Apartment - Upper Limit Package B ________ 21
Table 9-1 Recommended Acceptable Treatment Packages for Freight Rail Noise _______________ 24
Table 9-2 Example Construction for Freight Rail Noise ____________________________________ 25
Lloyd George Acoustics
List of Figures
Figure 3-1 Location of Noise Measurements _____________________________________________ 5
Figure 3-2 Spectral Content of Train Pass-by – LAeq ________________________________________ 7
Figure 3-3 Spectral Content of Train Pass-by – LAmax _______________________________________ 8
Figure 5-1 Comparison of LAmax Versus LAeq - Up to 2 Train Movements Per Hour_______________ 12
Figure 5-2 Comparison of LAmax Versus LAeq - Up to 4 Train Movements Per Hour_______________ 13
Figure 6-1 Comparison of LAmax Versus LAeq - Measured vs Guidelines ________________________ 14
Figure 9-1 Recommended Land Use Planning Guidance for Freight Rail Noise _________________ 23
Appendices
A
Acceptable Treatment Packages
B
Terminology
Lloyd George Acoustics
1 INTRODUCTION
In 2009 the State Planning Policy 5.4 Road and Rail Transport Noise and Freight Considerations in
Land Use Planning (SPP 5.4) was gazetted and provided a whole-of-government assessment
approach for noise impacts associated with road and rail transportation. The objectives of SPP 5.4
include protecting people from unreasonable levels of transport noise and protecting major
transport corridors and freight operations from incompatible urban encroachment. Early drafts of
SPP 5.4 contemplated the inclusion of a maximum noise level criteria (LAmax), which would apply in
addition to the day and night average noise level criteria (LAeq(Day) & LAeq(Night)). However, the LAmax
criteria was removed during stakeholder consultation. For road and passenger rail traffic there are
generally sufficient numbers of vehicle movements for the LAeq value to reasonably represent the
noise impact. However, freight rail can be subject to a relatively low number of movements, which
results in low LAeq noise levels when averaged over a long time period.
Freight rail noise is typically characterised by infrequent train pass-bys, which generally result in
sharp increases in noise, at levels that are significantly higher than the background noise
environment. it is this sudden increase in noise that can cause disturbance inside dwellings (and
other noise-sensitive premises). Sleep disturbance is a primary area of concern, as this can lead to a
range of associated negative health effects. LAmax noise levels are often used to assess these
impacts, because they are known to have a strong correlation with sleep disturbance and to
awakenings during sleep.
The SPP 5.4 Guidelines require noise impacts to consider a minimum of one train movement per
hour, irrespective of whether these numbers of movements are forecast or not. This is partly to
ensure that reasonable, long term utilisation of a freight rail line is not compromised when a noise
assessment is undertaken. However, it is Lloyd George Acoustics’ understanding that this
assessment approach was also adopted as a way of taking into account the fact that a low use track
might still have a significant acoustic impact on nearby noise sensitive land uses. The intent was that
SPP 5.4 would, by default, address LAmax impacts, by artificially increasing the LAeq value in these
cases.
A key question for the Freight and Logistics Council is whether the current approach adopted by
SPP 5.4 (and the associated Guidelines) adequately addresses LAmax impacts from freight rail. If not,
the question is then asked, under what circumstances is the existing policy approach inadequate at
addressing LAmax freight rail impacts. This report attempts to answer these key questions. Such
questions are critical if freight rail corridors are to be protected from inappropriate urban
development, since increasing residential complaints and pressure on freight rail operations is likely
to be the result if these noise impacts are not properly ameliorated.
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Lloyd George Acoustics
2 CRITERIA
The criteria relevant to freight trains in Western Australia is the State Planning Policy 5.4 Road and
Rail Transport Noise and Freight Considerations in Land Use Planning (and the associated Guidelines)
produced by the Western Australian Planning Commission. The objectives of SPP 5 4 are to:
•
Protect people from unreasonable levels of transport noise by establishing a standardised
set of criteria to be used in the assessment of proposals;
•
Protect major transport corridors and freight operations from incompatible urban
encroachment;
•
Encourage best practice design and construction standards for new development proposals
and new or redevelopment transport infrastructure proposals;
•
Facilitate the development and operation of an efficient freight network; and
•
Facilitate the strategic co-location of freight handling facilities.
The Policy’s outdoor noise criteria are shown in Table 2-1. These criteria apply at any point 1-metre
from a habitable façade of a noise sensitive premises and in one outdoor living area. Compliance
with these criteria are to give regard to a 15-20 year transport horizon.
Table 2-1 Outdoor Noise Criteria
Period
Target
Limit
Day (6am to 10pm)
55 dB LAeq(Day)
60 dB LAeq(Day)
Night (10pm to 6am)
50 dB LAeq(Night)
55 dB LAeq(Night)
Note: The 5 dB difference between the target and limit is referred to as the margin.
In the case of new noise sensitive developments constructed within the vicinity of a freight rail
corridor, the objectives of SPP 5.4 is to achieve •
acceptable indoor noise levels within residential buildings of 35 dB LAeq(Night) in bedrooms and
40 dB LAeq(Day) in other habitable rooms; and
•
a ‘reasonable’ degree of acoustic amenity in at least one outdoor living area on each
residential lot.
In the 2005 draft version of SPP 5.4, the LAmax outdoor criteria were a 75 dB target and 80 dB limit,
which applied equally day and night.
Reference: 14113026-02 Final.docx
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Lloyd George Acoustics
3 NOISE MEASUREMENTS
It was considered that the most appropriate way to answer the Freight & Logistics Council’s
questions was to examine some real measured data of freight trains on a low usage track.
Noise level measurements were undertaken alongside a freight railway in the vicinity of Robbs Road
Jetty (refer Figure 3-1), where trains travel to and from the North Quay Rail Terminal at Fremantle
Port 1 . It was proposed to construct multi-residential apartments on this site and similar
developments are occurring in this vicinity within the Cockburn area. As part of earlier work by
another consultant, a buffer distance of 15 metres from the edge of the railway reserve to noise
sensitive development was set (mainly to minimise vibration impacts), representing a distance of
approximately 25 metres from the track. So noise measurements were taken at this distance of 25
metres from the track.
Noise Level Measurements
Figure 3-1 Location of Noise Measurements
Table 3-1 provides the results of the noise level measurements recorded by the automatic noise
data logger in free-field conditions.
Table 3-1 Noise Logging Results: 25m From Railway
Date
No. of Pass-bys
(Night / Day)
Time
LAFmax, dB
18:40
81.4
14 November 2013
20:54
72.9
14 November 2013
22:57
75.1
0:24
67.7
5:31
90.2
14 November 2013
2
15 November 2013
15 November 2013
3
LAeq(Day) / LAeq(Night), dB
N/A
48.8
1
Currently train movements along this rail line service either the Kwinana Port or the Forrestfield Intermodal Terminal. In the past, trains
have also accessed this line for train movements to/from Kalgoorlie.
Reference: 14113026-02 Final.docx
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Lloyd George Acoustics
Date
No. of Pass-bys
(Night / Day)
Time
LAFmax, dB
10:22
83.3
10:56
77.7
15 November 2013
14:19
84.3
15 November 2013
17:56
77.4
22:05
72.8
23:30
74.1
10:14
91.9
13:33
78.3
3:34
75.8
18 November 2013
5:29
89.4
18 November 2013
10:31
79.0
11:29
70.9
18 November 2013
15:23
87.0
18 November 2013
18:08
83.1
18 November 2013
22:22
79.0
23:31
72.3
19 November 2013
1:57
92.1
19 November 2013
5:29
89.6
19 November 2013
10:50
82.0
19 November 2013
11:19
69.8
14:20
90.5
19 November 2013
18:07
80.9
19 November 2013
20:42
76.0
19 November 2013
22:31
89.7
23:50
76.6
5:26
77.7
10:43
75.5
11:22
74.6
15 November 2013
15 November 2013
4
15 November 2013
44.6
2
15 November 2013
16 November 2013
40.8
2
16 November 2013
18 November 2013
44.8
2
18 November 2013
49.5
4
18 November 2013
46.5
4
19 November 2013
19 November 2013
5
3
20 November 2013
20 November 2013
52.8
6
20 November 2013
Reference: 14113026-02 Final.docx
LAeq(Day) / LAeq(Night), dB
47.8
49.7
49.8
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Lloyd George Acoustics
Date
No. of Pass-bys
(Night / Day)
Time
LAFmax, dB
20 November 2013
14:19
80.7
20 November 2013
17:58
93.2
20 November 2013
20:24
74.5
20 November 2013
21:54
89.4
22:47
71.7
5:34
80.5
10:39
84.2
20 November 2013
2
21 November 2013
21 November 2013
1
LAeq(Day) / LAeq(Night), dB
48.7
N/A
Note: N/A means incomplete LAeq(Day) time period at the start and the end of the measurement.
It should be noted that there was no train movements on Sunday 17 November 2013 and limited
movements on Saturday 16 November 2013. Of those train movements measured, 16 occurred
during the night time period (10pm to 6am), representing 40% of all movements, with 24
movements, or 60% of all total movements, during the day time period (6am to 10pm).
The noise logger also provided the spectral content of the noise and this is shown by Figures 3-2 and
3-3, representing the LAeq for a train pass-by and the LAmax level respectively. These spectral results
reflect the low frequency characteristics of freight rail noise and where vital for later calculations to
predict indoor noise levels (see Section 7). Also shown on the charts is the range of measured noise
levels, which can be quite significant, particularly in the case of the LAmax levels.
Figure 3-2 Spectral Content of Train Pass-by – LAeq
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Lloyd George Acoustics
Figure 3-3 Spectral Content of Train Pass-by – LAmax
From the measurements, the LAeq(Day) and LAeq(Night) for trains were calculated to be 46.7 dB and
48.4 dB respectively. For comparison to the criteria, which applies at 1-metre from a habitable
façade, the noise levels would be increased by 2.5 dB due to reflected noise from the façade. That
is, the LAeq(Day) and LAeq(Night) levels would be assessed as 49.2 dB and 50.9 dB respectively. The LAeq(Day)
level complies with the SPP 5.4 target outdoor noise criteria of 55 dB. However, the LAeq(Night) level
marginally exceeds the SPP 5.4 target outdoor noise criteria of 50 dB.
The maximum noise levels from passing trains ranged from 67.7 dB to 93.2 dB LAmax. The mean LAmax
noise level was calculated to be 80.3 dB, with the data set having a standard deviation of 7.0 dB. Of
all the measured train movements, 75% (30 out of 40) exceeded the LAmax outdoor noise target of
75 dB from the 2005 draft SPP 5.4. Almost half of all train movements (19 out of 40) exceeded the
80 dB LAmax outdoor noise limit.
Taking the mean, or average, to represent the wide range of LAmax values somewhat distorts the full
picture in respect to noise disturbance. Doing so would mean that close to 50% of all the trains
measured had a higher LAmax noise level. Ignoring all these noisier trains would likely result in an
under representation of the true noise impact from this rail line. So, for the purposes of the
subsequent analysis in this report, the mean plus one standard deviation ( + 1 ) has be used2. This
gives a representative LAmax value of 87.3 dB. (The impact of this decision to use the mean plus one
standard deviation value is further discussed in Section 8.1.) Including the façade correction of
2.5 dB, this results in an LAmax noise level of 89.8 dB.
2
Data that is normally distributed will be perfectly symmetrical around its mean. For normally distributed data, taking the mean plus one
standard deviation means that 84% of all trains would be expected to be less than (or equal to) this LAmax value, with only 16% of all trains
recording LAmax noise levels higher than this. In this circumstance, because the measured values are not perfectly symmetrical about the
mean, the mean plus one standard deviation captures 78% of all measured train movements.
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Lloyd George Acoustics
Note that the calculated LAeq(Day) and LAeq(Night) values are around 40 dB less than the LAmax value. This
difference in LAmax versus LAeq(Day)/LAeq(Night) noise levels is much greater than would be expected for
major roads or passenger rail. This highlights the problem of using LAeq values to assess freight rail
noise. The infrequency of freight train movements means that long term LAeq averaging tends to
under play the real impact of these freight train pass-bys, thereby under representing the
annoyance/disturbance caused.
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Lloyd George Acoustics
4 ASSESSMENT OF NOISE MEASUREMENTS
The measured noise levels are determined to be 49.2 dB LAeq(Day), 50.9 dB LAeq(Night) and 89.8 dB LAmax
(including facade correction). It is understood that at the time of the measurements (in 2013) there
were nominally 8 train movements per day on this section of the rail line, although operationally this
varied somewhat. The SPP 5.4 requires that consideration be given to a 15-20 year planning
horizon. In many cases, obtaining forecast movements for freight trains is difficult, however in this
case, the following information was provided:
•
Current freight train movements (2015) are 6 per day, Mondays to Saturdays with a typical
train length of 600 metres (50 TEU’s per train). Total trade through Fremantle Port is
currently 700,000 TEU’s (Twenty foot Equivalent Unit), with the freight train modal split
currently representing 13% of this total (i.e. 91,000 TEU’s per annum via rail).
•
There is a government initiative to increase freight train movements to represent 30% of
Port trade (210,000 TEU’s). This equates to 7 movements per day, 7 days a week with a
train length in the order of 850 metres (80 TEU’s per train).
•
Future trade through the Port is expected to increase to 1,200,000 TEU’s per annum.
Assuming 30% of these are by freight rail (360,000 TEU’s), this would require 12 movements
per day of the 850 metre long trains.
Because the trains become longer in the future scenario, and operate on a 7 day week schedule, the
number of train movements is lower than would be the case if the trains remained at the same
length. Whilst it would be operationally inefficient if the 360,000 TEU’s remained on trains carrying
50 TEU’s, for comparative purposes this would equate to 20 train movements per day.
As discussed earlier, the SPP Guidelines requires it to be assumed that there is at least 1 train
movement per hour (24 movements per day). As the SPP assumption is greater than the forecast
number of movements, the 1 movement per hour assumption is used in the analysis. Table 4-1
provides the daily noise levels by increasing the actual number of movements noted in Table 3-1 to
16 during the day and 8 during the night (i.e. 1 per hour).
Table 4-1 Noise Logging Results Adjusted to 1 Movement Per Hour: 25m From Railway
Date
LAeq(Day)
LAeq(Night)
15 November 2013
50.6
53.0
16 November 2013
53.8
46.8
18 November 2013
52.5
55.6
19 November 2013
52.9
55.8
20 November 2013
54.1
54.0
21 November 2013
-
54.8
Average
52.8
53.3
Note: LAeq(Night) is calculated from 10pm on the previous date to 6am on the date shown.
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Lloyd George Acoustics
Including the façade correction, and allowing for 1 train movement per hour, the noise levels at 25
metres would be 55.3 dB LAeq(Day) and 55.8 dB LAeq(Night), with the LAmax unchanged at 89.8 dB.
Assessing the noise levels against the SPP 5.4 criteria shows that during the day, noise levels are
compliant, being no more than the target (55 dB LAeq(Day)) when rounded, with night-time noise levels
being slightly above the limit (55 dB LAeq(Night)) when rounded to 56 dB LAeq(Night). Where noise is 6 dB
above the target, as night-time noise levels are in this instance, Acceptable Treatment Package B
(refer Appendix A) would be applicable.
Application of Package B is considered to provide an attenuation from outside to inside of up to
23 dB since the external noise level can be up to 58 dB LAeq(Night) and the internal design noise level is
35 dB LAeq(Night). That is, in this instance, the internal noise levels would be 32 dB LAeq(Day) and 33 dB
LAeq(Night).
Comparing the rounded LAmax noise level of 90 dB to the draft 2005 SPP 5.4, indicates an exceedance
of 15 dB (where the target was set at 75 dB). Assuming the same relationship between external and
internal acceptable noise levels (15 dB difference between outside and inside) applies equally to
LAmax as it does to LAeq, means that the internal design goal LAmax would be 60 dB. Applying the 23 dB
reduction of Package B to the assessed external maximum noise level results in an internal noise
level of 67 dB LAmax.
As such, under the above scenario, following the Policy requirements and requiring Package B,
would result in maximum noise levels being 7 dB above the design goal.
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Lloyd George Acoustics
5 MAXIMUM VERSUS AVERAGE NOISE LEVEL
From Section 4, it can be seen that for the example where noise is assessed at 25 metres from the
track, and on the assumption that the criteria is 50 dB LAeq(Night) and 75 dB LAmax, (as per the draft 2005
SPP 5.4), the LAmax criteria is more critical. To explore this issue further, Figure 5-1 shows how the
LAmax noise level varies with distance from the track compared to the LAeq(Night) noise level, depending
on number of movements per hour, in terms of their exceedance above the relevant criteria. Some
items to note that influence the analysis are:
•
0 m equates to the closest line of the track within the rail reserve.
•
The LAeq is based on the Table 4-1 analysis and is therefore specific to this section of track.
Where trains are longer, use different locomotive configurations, in different notch settings
or the like, the LAeq noise level will be different.
•
Train movements of 1 and 2 trains per hour are shown to align with the SPP 5.4 Guidelines.
•
It is assumed the LAeq will decay at a rate of 4 dB per doubling of distance.
•
It is assumed the LAmax will decay at a rate of 6 dB per doubling of distance.
•
If the criteria varies (e.g. external maximum noise level is 80 dB LAmax rather than 75 dB
LAmax), the relationship will also vary.
Figure 5-1 Comparison of LAmax Versus LAeq - Up to 2 Train Movements Per Hour
The chart of Figure 5-1 shows the following:
•
The LAmax external noise target is not satisfied until a distance of 135 metres from the track.
This is shown as the time when the red Lmax line reaches 0 dB exceedance.
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Lloyd George Acoustics
•
The LAeq(Night) criteria for 1 train movement per hour is not satisfied until a distance of 70
metres from the track, being when the dark blue 1/hr-Leq line reaches 0 dB exceedance.
•
The LAeq(Night) criteria for 2 train movements per hour is not satisfied until a distance of 115
metres from the track, being when the blue 2/hr-Leq line reaches 0 dB exceedance.
•
The LAmax criteria is always more stringent than the LAeq(Night) criteria for both 1 and 2 train
movements per hour, since the LAmax line is always higher than the 1/hr-Leq and 2/hr-Leq lines.
Figure 5-2 expands on the above analysis by also showing the Leq compliance curves for 3 and 4
movements per hour. 4 train movements per hour (i.e one train every 15 minutes) is assumed to
represent a realistic upper limit for operational activity on a freight rail line.
Figure 5-2 Comparison of LAmax Versus LAeq - Up to 4 Train Movements Per Hour
From Figure 5-2, the following additional comments can be made:
•
Considering a maximum of 4 train movements per hour, the LAmax criteria is more critical
than the LAeq(Night) criteria within a distance of 70 metres from the track. Beyond that
distance the LAeq(Night) criteria becomes more critical.
•
For 3 train movements per hour, the LAmax criteria is more critical than the LAeq(Night) criteria
within a distance of 105 metres from the track.
Figures 5-1 and 5-2 indicate that an LAmax assessment will be critical in many circumstances when
compared to a standard SPP 5.4 LAeq noise assessment.
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6 SPP GUIDELINES APPENDIX A
The outcome of the Section 4 and 5 analysis highlights that, for most scenarios that are likely to exist
along the Forrestfield to Fremantle Port track, the LAmax criteria may not be adequately addressed.
This is the case even under the assumption that there may, in the future, be up to 1 train movement
per hour, which is considered conservative based on forecast movements.
Appendix A of the SPP 5.4 Guidelines includes the following table to provide guidance on estimated
LAeq(Night) noise levels from a freight rail line, as part of a screening assessment tool.
Table 6-1 Estimated LAeqNight) Noise Levels Provided in SPP Guidelines
Movements
per day
Distance from Track (m)
10
20
30
40
50
100
200
300
1 per hour
(minimum)
65
61
59
58
57
53
49
46
2 per hour
68
64
62
61
60
56
52
49
* Noted as a typical mix of, S or Q, P and D, AB, DA etc or L Class locomotives, and number of wagons varying from 45 to 90. Notch
settings varying from 5-8.
The Guidelines give an estimated LAeq(Night) value at 25 metres from the track of around 60 dB for 1
train movement per hour, compared to the 56 dB used in this report. Figure 6-1 compares the
LAeq(Night) values from the Guidelines with the measured values calculated in this report, for 1 train
movement per hour.
Figure 6-1 Comparison of LAmax Versus LAeq - Measured vs Guidelines
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The values provided in the Guidelines are certainly higher (more conservative) than those that were
measured along the Forrestfield - Fremantle Port track. Therefore the relative difference between
the LAmax and LAeq values is not as great when the Guidelines values are applied. The key points from
Figure 6-1 are summarised below:
•
The LAeq(Night) criteria was satisfied at 70 metres from the track based on the measurements,
whereas this is now increased to around 150 metres for the Guidelines values.
•
The LAmax criteria is always more critical than the LAeq(Night) measured values, whereas at a
distance of around 105 metres the LAmax becomes less critical than the Guidelines LAeq(Night).
•
At a distance of 25 metres, and assuming 1 train movement per hour, the LAeq(Night)
exceedance is noted as 6 dB for the measured values. Therefore Acceptable Treatment
Package B would be applicable to development at this location. Using the Guidelines
LAeq(Night) values, the exceedance would be 10 dB, therefore Package C would be applicable.
Whilst the latter is more stringent, it is still insufficient to accommodate the 15 dB LAmax
exceedance.
The above demonstrates that an LAmax assessment will still be critical, in a range of situations, even if
the more conservative LAeq(Night) values mentioned in Appendix A of the SPP 5.4 Guidelines are
applied.
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Lloyd George Acoustics
7 APPLYING ARCHITECTURAL PACKAGES
The Acceptable Treatment Packages within the SPP 5.4 Guidelines (refer Appendix A of this report)
are applied as follows:
•
Package A – Where noise levels are within the margin (5 dB above the target), that is up to
60 dB LAeq(Day) and 55 dB LAeq(Night).
•
Package B – Where noise levels are up to 8 dB above the target (3 dB above the limit), that is
up to 63 dB LAeq(Day) and 58 dB LAeq(Night).
•
Package C – Where noise levels are up to 10 dB above the target (5 dB above the limit), that
is up to 65 dB LAeq(Day) and 60 dB LAeq(Night).
The Packages, however, are a deemed-to-comply standard and are therefore generally considered
conservative. For many projects, where a house plan is provided to a consultant, the level of
architectural treatment can generally be reduced. As such, the internal noise level provided by the
deemed-to-comply Packages may in fact be less than the design goals of 35 dB LAeq(Night) in bedrooms
and 40 dB LAeq(Day) in other habitable rooms.
From the measurements, Table 7-1 provides the external noise spectra used in the calculations,
representing the external noise level at 25 metres from the track and assuming 1 train movement
per hour. Note that, for the purpose of these calculations, these values do not include a façade
correction.
Table 7-1 External Noise Spectra for Freight Trains
Octave Band Centre Frequency (Hz)
Parameter
dB(A)
31.5
63
125
250
500
1k
2k
4k
8k
16k
LAeq(Day) /
LAeq(Night)*
65
70
60
49
47
47
45
44
38
32
53
LAmax
94
102
91
82
81
83
81
77
71
62
87
* Assumes 1 train movement per hour.
To undertake the calculations, knowledge of the room size is required. Table 7-2 provides these on
the basis of ‘typical’ apartments. Higher end apartments are more likely to have larger glazing to
floor ratios.
Table 7-2 ‘Typical’ Apartment Room Dimensions
Description
Bedroom
Living
Floor Area
3.4m x 3.6m = 12.24m2
3.7m x 4.3m = 15.91m2
Glazing
2.4m x 1.4m = 3.36m2 (27% of floor area)
2.9m x 2.2m = 6.38m2 (40% of floor area)
Room Volume
31.8m3
41.4m3
Reverberation Time
0.5 seconds
0.5 seconds
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The computer programme Insul has been used to calculate the internal noise level on the basis of
applying the Package B requirements, as outlined in the SPP 5.4 Guidelines. For multi-storey
apartments, there may be a number of floors of apartments where the only noise paths are through
the walls and glazing, whereas the top floor will also have contribution through the roof/ceiling
structure. Table 7-3 provides the calculated internal noise levels.
Table 7-3 Calculated Internal Noise Levels – Typical Apartment
Room
Lower Level Apartment
Top Floor Apartment
LAeq, dB
LAmax, dB
LAeq, dB
LAmax, dB
Bedroom
25
57
34
66
Living
30
62
35
67
The results show the importance of the roof/ceiling contribution, which can dramatically increase
noise levels. Currently the SPP 5.4 Guidelines do not specify the type of roof, so either Colorbond or
clay tiles could be used. However, because of the low frequency component of freight rail, the use
of Colorbond, as assumed in these calculations, will result in significant contribution via the
roof/ceiling noise pathway.
Taking the worst-case top floor apartment, the calculated indoor noise levels are 34 dB LAeq(Night) in
bedrooms and 35 dB LAeq(Day) in living areas, both of which comply by 1 dB and 5 dB with the design
goal of 35 dB LAeq(Night) and 40 dB LAeq(Day) respectively. The LAmax in bedrooms is 6 dB above the design
goal of 60 dB LAmax, whilst in living areas there is a 7 dB exceedance3.
Section 4 applied a 23 dB reduction from outside (reflected noise level) to inside. For the worst-case
top floor apartment, the noise reduction is 22 dB LAeq to bedrooms, 21 dB LAeq to living areas, 24 dB
LAmax to bedrooms and 23 dB LAmax to living areas. This aligns reasonably well with the assumed
acoustic performance of Package B. Where there is negligible ceiling contribution (e.g. lower level
apartments), the noise reduction can be 5 to 9 dB higher.
As expected, the analysis shows that the deemed-to-comply construction is adequate, in this
instance, for LAeq noise levels, but inadequate for LAmax noise levels.
As discussed, the major weakness is the roof/ceiling construction, due to the assumed Colorbond
roof sheeting. Standard Colorbond roof/ceiling construction would have an acoustic performance of
approximately Rw + Ctr 44 + (-9) = 35. By comparison, a roof/ceiling construction with a clay roof tile
would have a typical performance of Rw + Ctr 37 + (-2) = 35. Although the overall acoustic
performance appears to be the same (Rw + Ctr is 35 in both cases), the lesser Ctr number indicates a
much better low frequency performance for the clay tile roof. To make this point more clearly,
standard roof/ceiling construction with Colorbond sheeting has a transmission loss of 7 dB at 63 Hz,
whereas with clay roof tiles the transmission loss increases to 22 dB. Given that freight rail contains
a significant amount of noise at this frequency, the low frequency characteristics of the building
become critical. To achieve an equivalent level of acoustic performance with a Colorbond roof
3
There may be some argument that the LAmax in a living area is not as critical for the protection of residential amenity, since maximum
noise impacts are often considered, primarily, a sleep disturbance issue.
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would require 4mm compressed fibre cement sheeting to be installed between the Colorbond and
the roof purlins and the ceiling construction to comprise 2 layers of 10mm plasterboard.
With a clay tile roof (or equivalent) in place, the calculated internal noise levels reduce by 5 and
7 dB, to 59 dB LAmax in bedrooms and 62 dB LAmax in living areas. To achieve no more than 60 dB LAmax
in living areas would require the glazing to be upgraded, so that it was equivalent to the
requirements for the bedrooms. Recommended improved architectural treatment packages for
freight rail are provided in Section 9 of this report.
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8 Sensitivity Analysis
To present the analysis of Sections 3 to 7, a number of assumptions have had to be made, each of
which will result in different effects if changed. Some of the critical assumptions are discussed in
this section of the report.
8.1
Analysis of Measured Data
The process of measuring the LAeq generally involves the following method:
•
Setting up a noise logger on the subject site for a period of 4-7 days;
•
For each complete day and night period, the LAeq(Day) and LAeq(Night) of trains is calculated, with
these calculated values being the logarithmic average of each time period; and
•
Each LAeq(Day) and LAeq(Night) value is then arithmetically averaged to obtain an overall value for
the entire measurement period.
Using the above approach for the Section 4 data meant that the average noise level was 53.3 dB
LAeq(Night), however there was a worst-case level of 55.8 dB LAeq(Night) being 2.5 dB higher. In this case,
the change in LAeq(Night) would still have resulted in Acceptable Treatment Package B being applied,
however there would be some cases where taking a worst-case value would change the
architectural treatment package required.
Analysis of the LAmax is even more critical, as the range of noise levels is much larger. For instance, in
the data set of Section 3, the range of values was 67.7 to 93.2 dB LAmax, with a mean of 80.3 dB LAmax.
Of the 40 measured trains, 19 had a maximum noise level above the mean, with 9 having a
maximum noise level of more than 87.3 dB(A), being the mean plus one standard deviation ( +
1 ). The latter was considered reasonable for the analysis in this report, however using the mean or
the highest maximum value (or any other statistical value) would significantly affect the results of
this analysis.
For instance, the LAeq(Night) was assessed as 56 dB (with façade correction), which exceeds the target
by 6 dB. By comparison, if the mean LAmax was used (with façade correction) this would exceed the
design goal of 75 dB LAmax by 8 dB. Whilst this means the LAmax is still more critical than the LAeq(Night),
the difference between the two assessment methods is now not as large as assumed in the earlier
analysis of results, which took the LAmax value to be the mean plus one standard deviation of the
measured values. Hence, using the mean LAmax would tend to soften the findings of this report.
Conversely, if the highest LAmax was used (i.e. 96 dB LAmax with facade correction), the LAmax level
would exceed the criteria by 21 dB rather than the 15 dB determined by this report.
8.2
Maximum Noise Criteria
The analysis has used a target criteria of 75 dB LAmax outside, deemed to be equivalent to 60 dB LAmax
inside. The basis of this is from the draft 2005 version of SPP 5.4 where the 75 dB LAmax criteria was
proposed. Two other relevant criteria are the World Health Organisation (WHO) and Australian
Standard 2021-2015 Acoustics – Aircraft Noise Intrusion – Building Siting and Construction (AS 2021).
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The WHO Guidelines recommend that, for the prevention of sleep disturbance, internal LAmax noise
levels should not exceed 45 dB more than 10 times per night. For this particular study, there would
then be no LAmax criteria applicable to freight train activity, since, even assuming a worst-case of 1
train movement per hour, there would only be 8 movements at night.
It could be argued that LAmax impacts from freight rail activity are not too dissimilar to the
disturbance experienced from aircraft. Appendix E of AS 2021, provides the following sliding scale in
terms of daily aircraft maximum noise levels:
•
70 dB LAmax outside is acceptable where there are more than 30 events per day;
•
80 dB LAmax outside is acceptable where there are between 15 and 30 events per day; and
•
90 dB LAmax outside is acceptable where there are less than 15 movements per day.
An important point to note is that any movement at night (7pm to 7am) counts as being the
equivalent of 4 events. This would mean that, from the monitoring data, where there are typically 4
movements between 7am and 7pm and 4 movements between 7pm and 7am, this would be
assessed as a total of 20 events. The forecast is to increase movements to 12 per day, which, if you
assumed an even split of 6 during the day and 6 at night, would equate to 30 events. In both cases,
80 dB LAmax would be deemed to be an acceptable external noise level, if the AS2021 approach was
applied.
Using 80 dB LAmax as the criteria would mean that the calculated LAmax of 87 dB would exceed the
criteria by 7 dB, compared to the LAeq(Night) level exceeding the SPP 5.4 target by 6 dB. (Note that
AS 2021 requires measurements to be at least 3.5 metres away from reflecting surfaces so the 2.5
dB façade correction has not been applied to the calculated LAmax.) Using the AS 2021 criteria, in this
instance, shows that the LAmax and LAeq(Night) are reasonably similar in impact.
If the approach of assuming at least 1 movement per hour was considered, this would equate to 60
events under AS 2021 and therefore 70 dB LAmax would become the applicable criteria. In which
case, 87 dB LAmax would exceed the criteria by 17 dB. So, in this case, an LAmax assessment becomes
much more critical than an LAeq(Night) assessment.
AS 2021 also sets indoor design sound levels of 50 dB LAmax for sleeping areas and 55 dB LAmax for
other habitable spaces, which is more stringent than the internal design goal of 60 dB LAmax used as
the basis for this assessment of freight rail noise.
8.3
Glazing to Floor Ratio
The calculations of Section 7 assume a ‘typical’ glazing ratio to floor area of 27% to bedrooms and
40% to living areas. If these were to increase to 40% for bedrooms and 60% for living areas, the
internal noise levels would change, as shown by Table 8-1.
For bedrooms, internal noise level increases are predicted, however these are reasonably small (by
no more than 1 to 2 dB). For living areas, the performance of the glazing is required to change to Rw
+ Ctr 31 in accordance with the SPP 5.4 Guidelines, whereas previously it was Rw + Ctr 28. This results
in internal noise levels actually decreasing in living areas but only by a small margin (by no more
than 1 dB).
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Table 8-1 Calculated Internal Noise Levels – Larger Glazing
Room
Lower Level Apartment
Top Floor Apartment
LAeq, dB
LAmax, dB
LAeq, dB
LAmax, dB
Bedroom
26
59
34
66
Living
29
61
35
67
Bedroom glazing comprises 40% of floor area and living glazing 60% of floor area.
Since the Acceptable Treatment Packages in the SPP 5.4 Guidelines work on a sliding scale, where
the acoustic requirements for windows vary according to the percentage of the floor area, changing
the window size is adequately controlled within Package B, in this instance.
8.4
Upper Limit of Packages
For the example in this report, it was determined that the LAeq(Night) was 56 dB and the LAmax was
90 dB (refer Section 4). In applying the SPP 5.4 Guidelines, the calculated 56 dB LAeq(Night) meant that
Acceptable Treatment Package B was applicable, however the same treatment package would also
apply if noise levels were at the upper limit of Package B. That is, if the development was to occur at
around 17 metres from the railway (instead of at 25 metres) the external noise levels would be
58 dB LAeq(Night) and 93 dB LAmax. Table 8-2 shows the predicted internal noise levels in a typical
apartment, assuming that the external LAeq(Night) levels are at upper limit of Package B. Note that LAeq
levels are 2 dB higher than those given in Table 7-3 and LAmax levels are 3 dB higher.
Table 8-2 Calculated Internal Noise Levels – Typical Apartment - Upper Limit Package B
Room
Lower Level Apartment
Top Floor Apartment
LAeq, dB
LAmax, dB
LAeq, dB
LAmax, dB
Bedroom
27
60
36
69
Living
32
65
37
70
Table 8-2 indicates that, even when assessed only against the LAeq(Night) criteria in SPP 5.4, the existing
Acceptable Treatment Package B may be inadequate in addressing freight rail noise for a top floor
apartment, since the acceptable indoor noise objective of 35 dB LAeq(Night) in bedrooms is exceeded.
As discussed in Section 7, additional acoustic treatment to the roof/ceiling construction and to living
area windows would be required to properly attenuate LAmax noise levels from freight rail. With
these acoustic improvements in place, but with external noise levels at the upper limit of Package B,
the resultant LAmax internal noise levels are predicted to be 62 dB LAmax in bedrooms and 63 dB LAmax
in living areas. Hence the acoustic performance of the window glazing in both bedrooms and living
areas would need to be further improved by 3 dB to achieve an internal noise level of no more than
60 dB LAmax.
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9 CONCLUSION
The analysis presented in this report shows that the SPP 5.4 assessment method is generally not
adequate in addressing LAmax noise impacts from freight trains. It shows that, if an LAmax criteria were
introduced for freight rail noise, in most situations it would dictate compliance when compared to
the existing LAeq assessment approach specified by SPP 5.4. This report also demonstrates that the
architectural treatment packages provided by the SPP 5.4 Guidelines would be inadequate in
achieving reasonable internal LAmax noise levels.
Recommended architectural treatment packages for residential development have been developed
specifically to address LAmax noise impacts from freight trains and are provided in Table 9-1. These
packages aim to achieve an indoor design sound level of 60 dB LAmax in both bedrooms and living
areas. To aid understanding, an example form of construction is provided in Table 9-2 to show how
the recommended architectural treatment packages for freight rail might be applied in practice.
Tables 9-1 and 9-2 should be read in conjunction with Figure 9-1, which provides recommended land
use planning guidance to assist in applying these packages.
The recommended architectural treatment packages and the associated land use planning guidance
is not intended to replace any requirements or criteria in SPP 5.4. Rather, their purpose is to help
fully inform land use planning along rail freight lines. It is anticipated that they could be used by
local government and developers to maintain an appropriate level of amenity within residential
developments alongside freight rail lines.
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Figure 9-1 Recommended Land Use Planning Guidance for Freight Rail Noise
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Table 9-1 Recommended Acceptable Treatment Packages for Freight Rail Noise
Area
Orientation to Road
or Rail Corridor
Freight Rail Package CF (up to 92 dB LAmax)
Freight Rail Package BF (up to 88 dB LAmax)
Freight Rail Package AF (up to 80 dB LAmax)
•
Walls to Rw + Ctr 50.
•
•
•
•
Walls to Rw + Ctr 45.
•
•
•
Windows and external door systems:
Minimum Rw + Ctr 28 total glazing up
to 40% of room floor area. Rw + Ctr 31
if 60%.
Roof and ceiling to Rw + Ctr 35.
Mechanical ventilation.
•
Windows and external door systems:
Minimum Rw + Ctr 34 total glazing up
to 40% of room floor area. Rw + Ctr 37
if 60%.
Roof and ceiling to achieve minimum
transmission loss of 22dB at 63Hz and
overall Rw + Ctr 35 (e.g. clay roof tiles).
Mechanical ventilation.
•
•
Facing
•
All Habitable
Rooms (Including
Kitchens)
Side
Opposite
Reference: 14113026-02 Final.docx
•
Walls to Rw + Ctr 45.
Windows and external door systems:
Minimum Rw + Ctr 30 total glazing up
to 40% of room floor area. Rw + Ctr 33
if 60%.
Roof and ceiling to achieve minimum
transmission loss of 22dB at 63Hz and
overall Rw + Ctr 35 (e.g. clay roof tiles).
Mechanical ventilation.
As above.
•
As above.
•
As above.
As above, except glazing may be 3 dB
less, or % increased by 20% (i.e. Rw +
Ctr 34 for 60%).
•
As above, except glazing may be 3 dB
less, or % increased by 20% (i.e. Rw +
Ctr 29 for 60%).
•
As above, except glazing may be 3 dB
less, or % increased by 20% (i.e. Rw +
Ctr 28 for 60% or Rw + Ctr 31 for 80%).
•
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Table 9-2 Example Construction for Freight Rail Noise
Orientation to Road
or Rail Corridor
Area
Freight Rail Package CF (up to 92 dB LAmax)
•
•
•
Walls: 2 x 110mm double brick wall
with 50mm cavity and 50mm
fibreglass insulation within the cavity.
Window: 10.5mm VLam Hush awning
windows (up to 40% of room floor
area).
External Doors: 10mm fully glazed
hinged door (up to 20% of room floor
area).
External doors to bedrooms are not
recommended.
Roof and ceiling: Clay roof tiles with
sarking and 10mm plasterboard
ceiling, or, Colorbond roof sheeting
with sarking, 4mm fibre cement
sheeting fixed to the roof purlins and
2 x 10mm plasterboard ceiling.
Mechanical ventilation.
•
Walls: 2 x 90mm double brick wall
with 20mm cavity.
Windows: 6mm awning windows (up
to 40% of room floor area); or, 10mm
awning windows (up to 60% of room
floor area).
External Doors: 10mm sliding glass
doors (up to 20% of room floor area).
External doors to bedrooms are not
recommended.
Roof and ceiling: Clay roof tiles with
sarking and 10mm plasterboard
ceiling, or, Colorbond roof sheeting
with sarking, 4mm fibre cement
sheeting fixed to the roof purlins and
2 x 10mm plasterboard ceiling.
Mechanical ventilation.
•
As above.
•
As above.
•
•
As above, except Windows: 6mm awning windows (up
to 40% of room floor area); or, 10mm
awning windows (up to 60% of room
floor area).
External Doors: 6mm fully glazed
hinged door (up to 20% of room floor
area).
•
•
As above, except Windows: 6mm awning or 10mm
sliding windows (up to 40% of room
floor area); or, 6mm awning windows
(up to 60% of room floor area).
External Doors: 6mm sliding glass
doors (up to 20% of room floor area).
Where practicable, locate an outdoor
living area on the opposite side of the
rail corridor or in an alcove on the
side of the house.
•
•
•
Facing
•
•
All Habitable
Rooms (Including
Kitchens)
Side
Opposite
•
•
Outdoor Living Area
Reference: 14113026-02 Final.docx
Freight Rail Package BF (up to 88 dB LAmax)
•
•
•
•
•
Where practicable, locate an outdoor
living area on the opposite side of the
rail corridor or in an alcove on the
side of the house.
Freight Rail Package AF (up to 80 dB LAmax)
•
•
Walls: 2 x 90mm double brick wall
with 20mm cavity.
Windows: 6mm awning or 10mm
sliding windows (up to 40% of room
floor area); or, 6mm awning windows
(up to 60% of room floor area).
External Doors: 6mm sliding glass
doors (up to 20% of room floor area).
Roof and ceiling: Colorbond roof
sheeting with 10mm plasterboard
ceiling.
Mechanical ventilation.
•
As above.
•
•
As above, except Windows: 4mm awning or 6mm
sliding windows (up to 40% of room
floor area); or, 6mm awning or 10mm
sliding windows (up to 60% of room
floor area).
•
Where practicable, locate an outdoor
living area on the opposite side of the
rail corridor or in an alcove on the
side of the house.
•
•
•
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Appendix A
ACCEPTABLE TREATMENT PACKAGES
The packages and information provided on the following pages are taken from Implementation
Guidelines for State Planning Policy 5.4 Road and Rail Transport Noise and freight Considerations in
Land Use Planning; December 2014.
Where outdoor noise levels are above the target level, excluding the effect of any boundary fences,
the Guidelines propose acceptable treatment packages that may be implemented without requiring
detailed review. The packages are also intended for residential development only. At higher noise
levels or for other building usages, specialist acoustic advice will be needed.
The acceptable treatment packages are intended to simplify compliance with the noise criteria, and
the relevant package should be required as a condition of development in lieu of a detailed
assessment.
Transition between each package should be made on the basis of the highest incident LAeq(Day) or
LAeq(Night) value to the nearest whole number determined for the building development under
assessment.
Any departures from the acceptable treatment specifications need to be supported by professional
advice from a competent person that the proposal will achieve the requirements of the Policy.
With regards to the packages, the following definitions are provided:
•
Facing the transport corridor: Any part of a
building façade is ‘facing’ the transport corridor
if any straight line drawn perpendicular to its
nearest road lane or railway line intersects that
part of the façade without obstruction (ignoring
any fence).
•
Side-on to transport corridor: Any part of a
building façade that is not ‘facing’ is ‘side-on’ to
the transport corridor if any straight line can be
drawn from it to intersect the nearest road lane
or railway line without obstruction (ignoring any
fence).
•
Opposite to transport corridor: Neither ‘side on’
nor ‘facing’, as defined above.
Lloyd George Acoustics
Appendix B
Terminology
The following is an explanation of the terminology used throughout this report.
Decibel (dB)
The decibel is the unit that describes the sound pressure and sound power levels of a noise source. It
is a logarithmic scale referenced to the threshold of hearing.
A-Weighting
An A-weighted noise level has been filtered in such a way as to represent the way in which the
human ear perceives sound. This weighting reflects the fact that the human ear is not as sensitive to
lower frequencies as it is to higher frequencies. An A-weighted sound level is described as LA dB.
L1
An L1 level is the noise level which is exceeded for 1 per cent of the measurement period and is
considered to represent the average of the maximum noise levels measured.
L10
An L10 level is the noise level which is exceeded for 10 per cent of the measurement period and is
considered to represent the “intrusive” noise level.
L90
An L90 level is the noise level which is exceeded for 90 per cent of the measurement period and is
considered to represent the “background” noise level.
Leq
The Leq level represents the average noise energy during a measurement period.
LA10,18hour
The LA10,18 hour level is the arithmetic average of the hourly LA10 levels between 6.00 am and midnight.
The CoRTN algorithms were developed to calculate this parameter.
LAeq,24hour
The LAeq,24 hour level is the logarithmic average of the hourly LAeq levels for a full day (from midnight to
midnight).
LAeq,8hour / LAeq (Night)
The LAeq (Night) level is the logarithmic average of the hourly LAeq levels from 10.00 pm to 6.00 am on
the same day.
LAeq,16hour / LAeq (Day)
The LAeq (Day) level is the logarithmic average of the hourly LAeq levels from 6.00 am to 10.00 pm on the
same day. This value is typically 1-3 dB less than the LA10,18hour.
Rw
This is the weighted sound reduction index and is similar to the previously used STC (Sound
Transmission Class) value. It is a single number rating determined by moving a grading curve in
integral steps against the laboratory measured transmission loss until the sum of the deficiencies at
each one-third-octave band, between 100 Hz and 3.15 kHz, does not exceed 32 dB. The higher the
Rw value, the better the acoustic performance.
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Ctr
This is a spectrum adaptation term for airborne noise and provides a correction to the Rw value to
suit source sounds with significant low frequency content such as road traffic or home theatre
systems. A wall that provides a relatively high level of low frequency attenuation (i.e. masonry) may
have a value in the order of –4 dB, whilst a wall with relatively poor attenuation at low frequencies
(i.e. stud wall) may have a value in the order of -14 dB.
Satisfactory Design Sound Level
The level of noise that has been found to be acceptable by most people for the environment in
question and also to be not intrusive.
Maximum Design Sound Level
The level of noise above which most people occupying the space start to become dissatisfied with
the level of noise.
Chart of Noise Level Descriptors
Austroads Vehicle Class
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Typical Noise Levels
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