Minimal response levels for visual reinforcement audiometry in infants

Area of Science:

• Audiology
• Pediatric audiology
• Hearing science

Background:

• Accurate hearing assessment in infants is crucial for early intervention.
• Establishing normative data for hearing testing in infants is essential for identifying hearing loss.
• Visual reinforcement audiometry (VRA) is a common technique for pediatric hearing assessment.

Purpose of the Study:

• To establish normative minimal response levels (MRLs) for normal-hearing infants using insert earphone visual reinforcement audiometry (VRA).
• To compare infant MRLs with established adult values.
• To provide clinically relevant normative data for infant hearing screening.

Main Methods:

• 46 normally developing infants (33-50 weeks) with presumed normal hearing underwent VRA.
• Insert earphones delivered warble tone stimuli at 500 Hz, 1 kHz, 2 kHz, and 4 kHz.
• Audiometer calibrated to ISO 389-2 standards for insert earphones.

Main Results:

• Mean MRLs were 16 dB HL (500 Hz), 13 dB HL (1 kHz), 7 dB HL (2 kHz), and 6 dB HL (4 kHz).
• Standard deviations were approximately 6 dB across all frequencies.
• Infant MRLs were significantly higher at lower frequencies compared to adults, but did not vary with age.

Conclusions:

• Significant differences exist between infant and adult MRLs when using insert earphones for VRA, particularly at lower frequencies.
• The study provides normative MRL values for infant hearing assessment.
• These findings underscore the importance of age-appropriate normative data in pediatric audiology.