APPLICATION

Infant Hearing-Aid Validation

Confirming objectively that amplified speech is audible at the cortex in a baby who cannot report what they hear.

What the cortical response shows

  • Aided cortical responses present to all three tokens indicate the speech spectrum is audible; an absent token response flags an under-fitted region.[13]
0100200300400latency (ms)Unaided /t/Aided /t/
Free-field speech-token testing through the hearing aid: no response to the unaided high-frequency token, but a clear aided response — objective proof that amplified /t/ is now audible.

Why the cortical response here

  • Behavioural validation is unreliable in infants, so an objective check that the fitting delivers audible speech is needed.[12]
  • Speech tokens /m/, /g/ and /t/ sample the low-, mid- and high-frequency regions of speech; a response to each shows that region is audible through the aid.[13]

How it changes management

  • Token-by-token results guide fine-tuning of the fitting, and the awake-state requirement means testing is timed around the infant's settled, alert periods.[18]

TEACHING POINT

Aided CAEP turns 'we think the aid helps' into 'amplified /m/, /g/ and /t/ are objectively audible at the cortex' — invaluable when the patient is a baby.[12]

Sources for this page are listed on the References page. Browse all applications from the atlas home.