High-frequency sensitization of the acoustic reflex

Area of Science:

• Audiology
• Auditory Neuroscience
• Human Physiology

Background:

• The acoustic reflex protects the inner ear from loud sounds.
• High-frequency tones can influence the acoustic reflex.
• Previous research shows varied effects of high-frequency sensitization.

Purpose of the Study:

• To investigate high-frequency sensitization of the acoustic reflex.
• To examine the effect of a 6000 Hz sensitizing tone on acoustic reflex threshold and amplitude growth.
• To compare findings with previous investigations.

Main Methods:

• 10 normal-hearing subjects participated.
• A 6000 Hz tone was paired with activating frequencies (500, 1000, 2000 Hz).
• Acoustic reflex threshold and amplitude growth were measured.

Main Results:

• A 6000 Hz sensitizing tone reduced acoustic reflex threshold by 10-12 dB.
• This reduction was less than reported in similar prior studies.
• Sensitizing stimulation influenced acoustic reflex amplitude growth, especially near threshold.

Conclusions:

• High-frequency sensitization of the acoustic reflex is confirmed.
• Methodological variations in sensitizing tone presentation likely explain differing results.
• Sensitizing tones impact both the threshold and amplitude growth of the acoustic reflex.