Infants referred from their newborn hearing screen should receive a follow-up diagnostic audiological evaluation before 3 months of age. This evaluation serves to verify the existence of a hearing impairment, and when present, the etiology and severity.

Data show that an infant with a significant hearing impairment who receives intervention by 6 months of age will perform significantly better in language development than the infant who is identified after 6 months of age (Yoshinago-Itano et al, 1998)¹.

When should a Diagnostic Audiological be performed?

Diagnostic Audiology occurs after a baby fails to pass a follow-up rescreen, between 1 and 3 weeks of age. The diagnostic evaluation should occur between the ages of 1-3 months of age.

Some key Components in Diagnostic Audiology of Infants and Children

• Pediatric Audiologist

This refers to the Audiologist who is trained, has the technical expertise and desire to work with the infant population. The Audiologist performs an audiological test battery to include physiologic measures and developmentally appropriate behavioral techniques.
 

• Case History Documentation

A completed child and family case history to include congenital family history of hearing loss, medical factors, and risk indicators for hearing loss that may be present.
 

• Auditory Brainstem Response (ABR)

This should include: Clicks, Tone bursts, and Bone Conduction testing. (This technology reflects the activity of the cochlea, auditory nerve, and auditory brainstem pathways.)
 

• Otoacoustic Emissions (OAE)

(This technology is sensitive to outer hair cell dysfunction.)
 

• Acoustic Immittance Audiometry

Tympanometric capabilities that use probe tones greater than 220/226 Hz. This should also include acoustic reflexes using a higher frequency probe tone, such as 660 Hz or 800 Hz. (This technology assesses middle ear status.)
 

• Behavioral Audiometry

Visual reinforcement audiometry can be effectively used with infants as young as 5 months. A confirmatory audiologic test battery for infants and toddlers age 6 through 36 months should include this procedure in addition to the components previously mentioned. (This procedure assesses the infant/child?s behavioral response to auditory stimuli in a sound proof booth.)
 

• Audiological Monitoring

If a child has unilateral, mild, or chronic conductive hear loss or is "at risk" for progressive or delayed onset hearing loss, ongoing audiological services should include audiologic monitoring every 6 months until at least 3 years of age.

References

• Joint Committee on Infant Hearing
• http://www.tdh.state.tx.us/audio/diagnost.htm
• http://www.colorado.edu/slhs/mdnc/guidelines.html
• http://www.audiology.org/professional/positions/otitis.php
• http://www.asha.org/hearing/testing/
• http://www.asha.org/hearing/gen_audiology.cfm
• http://www.boystown.org/Btnrh/Chlc/baseval.htm
• http://www.boystown.org/Btnrh/Chlc/unilat.htm

O'Neal,J., Fititzo,T., & Litman,T. (2000). Neonatal Hearing Screening: Follow-Up and Diagnosis: In: R.J. Roeser, M. Valente, H. Hosford-Dunn (ed.) Audiology Diagnosis, (pp. 527-544).New York, New York: Thieme.

Yoshinaga-Itano, C., Sedey, A., Coulter, D.K., & Mehl, A. L. (1998). Language of early and later identified children with hearing loss. Pediatrics, 102, 1161-1171.