Further Acoustic Advice

Page 2

We understand that the wing/side walls as previously recommended will be
constructed, and have reviewed the plans by Cab Roto. The plans show the acoustic
barriers will be internally lined with acoustically absorbent material. This will have
multiple benefits for the site:
         Increased barrier attenuation to the units to the sides of the Premises;
         Reduced localized reverberation and therefore radiation of noise from the
          outdoor area; and
         Reduced patron speech levels due to lower ambient noise in the outdoor
          area.
It is considered that the “evening” noise criterion should now be applied as the most
stringent to be achieved. The evening noise period by definition ceases at 10:00 pm.
However, given that trade until 10:30 pm would only be on weekend evenings,
background noise during the period from 10:00 pm until 10:30 pm is unlikely to be
significantly different from pre-10:00 pm, and at worst could be regarded as a
“shoulder” or transition period during which the evening background noise gradually
reduces with ambient activity.
The background noise levels reported previously were based on the quietest periods
that could be expected in that area, were deliberately carried out early in the week,
and excluded vehicular traffic, people, air conditioner noise etc., and are therefore
very conservative. During evenings with even light breezes, small levels of ambient
activity, or relatively consistent traffic along Gympie Terrace, background noise
levels are generally likely to range from 40-50 dB(A), with corresponding criteria of
50-60 dB(A).
Previously reported potential patron noise levels at the apartment overhead from
the Premises were 47-61 dB(A). There was an error transcribing these results from
the spreadsheet used to calculate them, and the actual predicted noise levels are 48-
58 dB(A) (which don’t make any material difference to our previous
recommendations). These predicted noise levels are 3-13 dB(A) higher than the
previously established evening criterion of 45 dB(A). However, on most evenings,
they are expected to be within the criteria based on the likely range of background
noise levels discussed above.
The acoustic wing wall barriers are the major component of the acoustic treatments
recommended due to the presently unobstructed line of sight from the dining area
to the neighbouring units. As such, it is our view that with the reduced trading
hours, the overhead treatment can be omitted from the recommendations made
previously without patron noise generally exceeding the background noise by
10 dB(A) at the overhead apartment, with the following exceptions:
         Particularly quiet evenings e.g. minimal road traffic combined with still
          weather; and
         When there are multiple patrons talking loudly in the outdoor area.
The staff would need to be aware of the significance of these circumstances, and the
noise management plan must reflect this.


RoadPro Acoustics                                                          ABN 50 319 930 318
1060 RGreen 20161010 Letter                                                        Page 2 of 3

Page 3

I trust this is sufficient for your present requirements. However, if you have any
further queries please contact me on 0416 132 51 or at [email protected] Sincerely




Joseph Carroll
B. Eng (Environmental) RPEQ (Civil) 7798
Member, Australian Acoustical Society




RoadPro Acoustics                                                   ABN 50 319 930 318
1060 RGreen 20161010 Letter                                                 Page 3 of 3