No Effect of Interstimulus Interval on Acoustic Reflex Thresholds.

Area of Science:

• Audiology
• Neuroscience
• Hearing Science

Background:

• The acoustic reflex (AR) is a key audiological test.
• AR thresholds (ARTs) are explored as noninvasive markers for cochlear synaptopathy.
• Measuring ARTs at high frequencies (4 kHz) is challenging due to response characteristics.

Purpose of the Study:

• To investigate the effect of interstimulus interval (ISI) duration on ARTs in normally hearing young adults.
• To determine if longer ISIs improve ART reliability and reduce threshold levels at 1 kHz and 4 kHz.

Main Methods:

• ARTs were measured in normally hearing young adults at 1 kHz and 4 kHz.
• Stimuli were presented with varying ISIs (2.5 s to 8.5 s).
• The impact of ISI on ART level and reliability was analyzed.

Main Results:

• Increasing ISI duration from 2.5 s to 8.5 s did not significantly alter ART levels.
• Longer ISIs did not improve the reliability of ART measurements.
• Clinically measured ARTs, even at 4 kHz, demonstrated excellent reliability with short ISIs.

Conclusions:

• Short interstimulus intervals (2.5 s) are adequate for obtaining sensitive and reliable acoustic reflex threshold measurements.
• Findings support the clinical utility of ARTs, including at high frequencies, for assessing hearing function.