Concentrated spectral energy damages the ear more than broadband noise of equal level
Evidence
This approach to measuring the noise dose takes no account of the spectrum of the sound that is causing the noise exposure, because to do so would be difficult in practice. However, it is obvious that the effect of a pure tone at 85 dBA on the ear is going to be different from the same level spread over the full frequency range. In the former situation, there will be a large amount of energy concentrated at a particular point on the basilar membrane, and this is likely to be more damaging than the second case, in which the energy will be spread out over the full length of the membrane. Note that the specification for noise dose uses “A” weighting for the measurement, which, although it is more appropriate for low rather than high sound levels, weights the sensitive 4 kHz region more strongly. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 688
Categorization
- XREF: Extends the basilar membrane tonotopic mapping ideas to a damage mechanism; also connects to the reader’s earlier material on One Square Inch of Silence re: noise damage mechanisms. — connects to: Increasing spectral contrast enhancement worsens cochlear implant performance.; A narrowband tone damages the ear more than the same energy spread wide; Perceptual insensitivity to low-frequency sound masks its physiological impact on the inner ear
- QUESTION: The 4 kHz weighting point suggests this frequency region is especially vulnerable; worth chasing why 4 kHz specifically.
- corroborated: 2 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 688