TY - JOUR
T1 - Digital sampling of acoustic impulse noise
T2 - Implications for exposure measurement and damage risk criteria
AU - Smalt, Christoper J.
AU - Brungart, Douglas S.
N1 - Publisher Copyright:
© 2022 U.S. Government.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - Current standards for the measurement of impulse noise (e.g., MIL-STD-1474E) recommend using a sampling rate of at least 200 kHz in order to accurately estimate the risk of hearing damage. The given motivation for this high sampling rate is to ensure a temporal resolution in the impulse waveform fine enough to accurately capture the peak pressure. However, the Nyquist-Shannon sampling theorem specifies that a sampled signal can accurately reconstruct both the amplitude and phase information of a signal given the sampling rate is at least twice the highest frequency present in the original signal. Thus, it is possible to reconstruct a band limited signal with the same temporal resolution as one captured at a higher sampling rate if the contributions of energy above the Nyquist rate can be ignored. In this study, resampling techniques are applied to a signal sampled at 48 kHz to extract A-weighted sound pressure energy estimates within 0.1 dB of those obtained at a higher sampling rate. Our results suggest sampling rates for impulsive noise should be based on the range of frequencies expected to make a contribution to injury risk rather than on concerns about temporal resolution.
AB - Current standards for the measurement of impulse noise (e.g., MIL-STD-1474E) recommend using a sampling rate of at least 200 kHz in order to accurately estimate the risk of hearing damage. The given motivation for this high sampling rate is to ensure a temporal resolution in the impulse waveform fine enough to accurately capture the peak pressure. However, the Nyquist-Shannon sampling theorem specifies that a sampled signal can accurately reconstruct both the amplitude and phase information of a signal given the sampling rate is at least twice the highest frequency present in the original signal. Thus, it is possible to reconstruct a band limited signal with the same temporal resolution as one captured at a higher sampling rate if the contributions of energy above the Nyquist rate can be ignored. In this study, resampling techniques are applied to a signal sampled at 48 kHz to extract A-weighted sound pressure energy estimates within 0.1 dB of those obtained at a higher sampling rate. Our results suggest sampling rates for impulsive noise should be based on the range of frequencies expected to make a contribution to injury risk rather than on concerns about temporal resolution.
UR - http://www.scopus.com/inward/record.url?scp=85137550723&partnerID=8YFLogxK
U2 - 10.1121/10.0013848
DO - 10.1121/10.0013848
M3 - Article
C2 - 36182325
AN - SCOPUS:85137550723
SN - 0001-4966
VL - 152
SP - 1283
EP - 1291
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
IS - 3
ER -