Speech Perception and Discrimination in Noise for Long-term Bilateral Hearing Aids Users: An ERP Study

This study investigated the characteristics of auditory event-related potentials (AERP) evoked by vowel and consonant contrasts in prelingual deafness adults, who fitted with bilateral hearing aids (HA) in quiet and noisy environments.

Standard stimuli /ba/ (75%) and deviant stimuli (/ga/ and /bu/, 12.5% each) were presented using a passive oddball paradigm in quiet and noisy (+10 decibel [dB] signal-to-noise ratio [SNR]) conditions. Eighteen young adults aged 18-23 years with long-term bilateral HA, and 20 age-matched normal hearing (NH) individuals participated in the study.

The hearing loss (HL) group showed lower N1-P2 and mismatch negativity (MMN) amplitudes and longer N1 and MMN latencies than the NH group. Both groups showed reduced N1-P2 amplitudes and longer MMN latencies in noise. The consonant contrast (/ga/-/ba/) induced lower and delayed MMN than the vowel contrast (/bu/-/ba/).

Young adult bilateral HA users with prelingual severe to profound HL have poorer abilities in processing consonant-vowel syllables than people with NH, especially in noisy conditions and consonant contrast differences. Long-term auditory compensation provided by bilateral HA for people with prelingual severe and profound HL does not seem to enable adequate development of the auditory cortex.