Adverse effects that do not involve the hearing organs may occur at which of the following sound levels?

Adverse effects that do not involve the hearing organs may occur at which of the following sound levels?

• A. 150 dB unweighted
• B. 145 dB in octave or 1/3 octave band
• C. 130 dB
• D. 160 dB

Answer: (B)

Non-auditory adverse effects from noise depend not just on how loud something is, but on how the energy is distributed across frequencies. When sound energy is concentrated in a single octave band (or 1/3 octave band) and reaches about 145 dB, that band can couple into the body in ways that trigger non-hearing effects. This band-limited threshold is the point at which these effects become likely, because the energy reinforces the body’s resonances and stress responses more effectively than a broad, broadband measurement. The other options miss this band-specific aspect. An overall broadband level such as 150 or 160 dB unweighted doesn’t pinpoint the spectral condition needed for non-auditory effects, and 130 dB is below the threshold where these effects typically occur. Hence, the band-limited level around 145 dB in an octave or 1/3 octave band best represents the onset of non-auditory adverse effects.

Non-auditory adverse effects from noise depend not just on how loud something is, but on how the energy is distributed across frequencies. When sound energy is concentrated in a single octave band (or 1/3 octave band) and reaches about 145 dB, that band can couple into the body in ways that trigger non-hearing effects. This band-limited threshold is the point at which these effects become likely, because the energy reinforces the body’s resonances and stress responses more effectively than a broad, broadband measurement.

The other options miss this band-specific aspect. An overall broadband level such as 150 or 160 dB unweighted doesn’t pinpoint the spectral condition needed for non-auditory effects, and 130 dB is below the threshold where these effects typically occur. Hence, the band-limited level around 145 dB in an octave or 1/3 octave band best represents the onset of non-auditory adverse effects.