The "overshoot" effect and sensory hearing impairment

Area of Science:

• Auditory Neuroscience
• Psychoacoustics
• Hearing Science

Background:

• The auditory overshoot effect describes the phenomenon where detecting a brief tone masked by a longer noise burst is more difficult when the tone is presented soon after the noise onset.
• This effect, first described by E. Zwicker, has implications for understanding temporal processing in the auditory system.

Purpose of the Study:

• To investigate the magnitude of the auditory overshoot effect in individuals with high-frequency unilateral or asymmetric hearing loss.
• To compare the overshoot effect between the better and more impaired ears in subjects with sensory hearing loss.

Main Methods:

• Six subjects with high-frequency unilateral or asymmetric hearing loss participated.
• Detection thresholds for 5-ms, 4-kHz tones were measured at various delay times (10, 200, 390 ms) after the onset of a 400-ms noise burst (2-8 kHz).
• Testing was conducted on both the better and impaired ears, with noise levels adjusted for sound pressure and sensation in the better ear.

Main Results:

• Thresholds for tone detection decreased monotonically with increasing delay time in all subjects and ears tested.
• The magnitude of the overshoot effect was consistently small, typically around 5 dB.
• A similar small overshoot effect was observed regardless of the degree of hearing impairment or which ear was tested.

Conclusions:

• The auditory overshoot effect is present even in individuals with high-frequency sensory hearing loss.
• The magnitude of the overshoot effect appears to be relatively preserved despite hearing impairment.
• These findings suggest that basic temporal masking mechanisms, like overshoot, may be robust across different hearing statuses.