Refining Stimulus Parameters in Assessing Infant Speech Perception Using Visual Reinforcement Infant Speech...

Area of Science:

• Audiology
• Speech Perception
• Infant Auditory Development

Background:

• Standardized speech perception measures are essential for audiological assessments in infants and young toddlers.
• A gap exists in prelinguistic, standardized speech perception assessments for clinical use in infants.
• Such measures are vital for evaluating the impact of early hearing loss identification and intervention on auditory pathways.

Purpose of the Study:

• To examine how sensation level (SL) affects normal-hearing (NH) infants' ability to discriminate /a-i/ and /ba-da/ speech sounds.
• To determine if performance on these two contrasts differs significantly in predicting speech discrimination criteria.

Main Methods:

• Employed survival analysis and repeated measures logistic regression models.
• Twenty-two NH infants (6-14 months) participated in two to three testing sessions.
• Visual reinforcement infant speech discrimination (VRISD) was used to assess discrimination at varying sensation levels (50, 60, 70 dBA).

Main Results:

• Infants discriminated the vowel contrast (/a-i/) at significantly lower SLs compared to the consonant contrast (/ba-da/).
• Six infants failed to reach criterion for /ba-da/, while only one failed for /a-i/.
• The logistic regression model indicated a higher likelihood of discriminating /a-i/ versus /ba-da/, even when controlling for SL.

Conclusions:

• Most normal-hearing infants can achieve speech sound discrimination at 60 dB SL for vowel contrasts.
• Higher sensation levels (≥70 dB SL) may be required for all infants to discriminate more challenging consonant contrasts.
• Findings inform the development of age-appropriate speech perception tests for audiological evaluations.