Publication Date:
2006-01-11
Description:
An objective method and apparatus for noise control and acoustic diagnostics of motorcar engines are reported. The method and apparatus let us know whether the noisiness of the vehicle under test exceeds the admissible threshold levels given by appropriate standards and if so what is the main source of the excessive noise. The method consists in measuring both the overall noise level and the sound pressure levels in definite frequency bands while the engine speed is controlled as well and may be fixed at prescribed values. Whenever the individually adjusted threshold level has been exceeded in any frequency band, a self-sustaining control signal is sent.
Keywords:
INSTRUMENTATION AND PHOTOGRAPHY
Type:
The 4th Natl. Conf. on Acoustics Vol. 1A (NASA-TT-F-15375); p 198-204
Format:
text
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