A single exposure of several hours duration to continuous music with an overall level of 100 dB SPL will most likely produce

• A. Tinnitus and a temporary threshold shift in high frequencies
• B. Tinnitus and a distortion of speech perception
• C. A temporary threshold shift in the low frequencies
• D. A permanent threshold shift

Answer: (A)

Loud noise exposure can temporarily raise the hearing threshold, especially for high frequencies, because the basal region of the cochlea (which codes high-frequency sounds) is more vulnerable to intense sound. Tinnitus is a common consequence after such noise exposure, even when the hearing loss is temporary. A single, several-hour exposure at 100 dB SPL is most likely to produce a temporary high-frequency threshold shift rather than a permanent one, since permanent damage generally requires either higher intensity, longer duration, or repeated exposure. So the most likely outcome is tinnitus accompanied by a temporary threshold shift in the high-frequency range.