Chintarmanya Vivian (VO)
APAUT3 - Listening Assignment 1
Question: Does budget acoustic treatment make a measurable improvement on the reverberation of a space?
For Voice Actors, the focus is to reduce reverberation time (the decay of sound in a room) with a RT60 (Reverberation Time) target of 0.2 seconds (Muffett, 2022) for a clear vocal.
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To demonstrate if budget treatment methods work (Harris-MacDuff, 2019), I have chosen two spaces to perform an RT60 measurement on: Control Room and Vocal Booth.
The Experiment
Measurements are demonstrated in this picture (including Mic and Speaker placement – chair was removed in this experiment):
Materials
Control Room
(Has semi-treatment)
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Mirror and Window: Glass
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Walls and Ceiling: Plasterboard
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Floor: Carpet
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Fabric venetian blinds.
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Wooden PC Desk.
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Vocal Booth.
Booth
(Has full treatment)
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2 Mattresses against wall.
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Walls and Ceiling: One layer of packing fabric (Wrap & Move) with a layer of cotton bedsheets.
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Wooden cupboard.
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Carpet Floor.
Audio clips to demonstrate clap for each space:
Control Room
Booth
Experiment Tools:
I used REQ Wizard to excite both spaces using the following setup:
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Sennheiser MK4 Microphone (no calibration file found and is a cardioid mic)
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Audient id14 Interface
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Logitech PC speakers Z213 – with subwoofer.
I have also used the AMROC calculator: https://amcoustics.com/tools/amroc to determine the absorption coefficient needed for each space:
Control Room
Booth
The Results:
RT60 (Blue is Control and Orange is Booth):
Waterfall - Control:
Waterfall - Booth:
The Conclusion:
As determined by the tests, it demonstrates that there is significant reduction in reverberation within the Booth compared to the Control Room. The most significant reduction in decay time occurs around the 2kHz to 10kHz area, with a NULL present in the 300Hz area.
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In conclusion, this experiment’s initial findings validate that budget treatment, such as moving blankets, do reduce reverberation within a space. However, further testing with specialised equipment is recommended to perform a more thorough analysis.