Hearing impairment and self-masking: listening during vocalization

Area of Science:

• Audiology
• Speech Science
• Hearing Science

Background:

• Self-produced vocalizations can interfere with auditory perception.
• Understanding the masking effect of speech sounds is essential for individuals with hearing impairment (HI).
• Previous research has not fully elucidated the impact of vocalization on masking in HI populations.

Purpose of the Study:

• To investigate the masking effect of a vocalized [a:] sound on noise bands and speech.
• To compare these masking effects in individuals with mild-to-moderate hearing impairment (HI) versus normal-hearing (NH) individuals.
• To assess the influence of different hearing loss configurations (high-frequency loss vs. low/mid-frequency loss) on masking.

Main Methods:

• Determined masked thresholds for noise bands (250-8000 Hz) and continuous discourse.
• Measured the amount of masking produced by the vocalized [a:].
• Identified the maximal vocalization level allowing subjects to follow continuous discourse.

Main Results:

• The vocalized [a:] produced significantly higher masked thresholds in subjects with high-frequency (HF) loss compared to normal-hearing (NH) subjects.
• Masking thresholds were also higher for HF loss subjects than for low-, mid-frequency (LMF) loss subjects.
• The overall amount of masking produced was significantly smaller in subjects with HI compared to NH subjects.

Conclusions:

• The masking effects of self-produced sounds, like vocalizations, are significant and must be considered in auditory rehabilitation strategies.
• These findings have implications for the future design of hearing aids to better accommodate the auditory environment of individuals with hearing impairment.
• Tailoring auditory rehabilitation and device design to account for vocalization-induced masking can improve speech understanding in HI individuals.