Cost-effective noise control in industrial workrooms may be achieved by predicting and
auralizing the soundfields generated by sources (e.g. equipment and fans) in the presence of
candidate acoustical treatments. Prediction techniques available to noise-control practitioners
range from computationally intensive but accurate ray-tracing and method-of-images models to
simpler, but less accurate, models based on diffuse-field theory and empirical models. The
auralization of industrial noise may be useful in demonstrating its negative effects. Auralization
(acoustical virtual reality) systems range from cheap but grossly inaccurate stereo systems to very
expensive but accurate digital-signal-processing engines. A combined noise prediction and
auralization system for industrial workrooms - PlantNoise" - that bridges this cost-performance
gap is presented here. New empirical noise-level and reverberation time prediction algorithms
based on measured sound propagation curves and reverberation times are developed. Prediction
accuracies approach those of the more complex models while calculation times are negligible.
Auralization of the predicted noise levels is effected on an IBM-compatible PC equipped with a
soundcard and headphones. Pink noise is generated at the same sound pressure level and
frequency content as the predicted levels (in octave bands from 125 Hz to 4 kHz), and then
presented to the system user over the headphones. The user experiences the predicted soundfield
(updated in real-time) during a computer 'walk-through' of the virtual workroom. A graphical
user interface enables visualization of the workroom floor plan, including sound sources and user
position. Predicted octave-band reverberation times and noise levels are displayed on the screen.
The total noise level at the user position is also displayed in dB or dBA. A contour map of the
total noise levels is displayed on the workroom floor plan at the user's request. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/5875 |
| Date | 05 1900 |
| Creators | Heerema, Nelson Raymond |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Format | 5640095 bytes, application/pdf |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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