Investigating peripheral sources of speech-in-noise variability in listeners with normal audiograms

Area of Science:

• Auditory Neuroscience
• Speech Perception
• Hearing Science

Background:

• Understanding speech-in-noise (SIN) deficits in normal-hearing listeners is crucial.
• Hypotheses include sub-clinical outer hair cell damage or inner hair cell-auditory nerve synapse degeneration.
• Investigating peripheral auditory function's role in SIN performance variability is key.

Purpose of the Study:

• To retrospectively investigate peripheral auditory sources of SIN deficits in young, normal-hearing listeners.
• To examine the relationship between noise exposure, hearing complaints, and SIN performance.
• To assess the predictive power of peripheral auditory measures on SIN performance.

Main Methods:

• Retrospective analysis of data from 194 young, normal-hearing participants.
• Collected case histories (noise exposure, SIN complaints, tinnitus, hyperacusis).
• Performed standard/extended high-frequency audiometry, distortion product otoacoustic emissions, auditory brainstem responses, and SIN tests.

Main Results:

• 42% reported SIN deficits, while 8% showed deficits based on performance.
• Noise-exposed listeners reported more hearing complaints and hyperacusis.
• No significant differences in extended high-frequency thresholds or auditory brainstem response amplitudes between noise-exposed and control groups.
• Peripheral auditory measures did not predict SIN performance.

Conclusions:

• Noise exposure is associated with hearing complaints in young, normal-hearing individuals.
• Peripheral auditory function, as measured, does not fully explain SIN performance variability.
• Further research is needed to identify underlying physiological mechanisms for SIN deficits.