Matt was a typically developing 9-month-old. He was born in a hospital at term and spent 48 hours in a general newborn nursery. He was not screened at birth for hearing loss. Matt presented with no risk factors for hearing impairment (ASHA, 1994). His parents were concerned, however, about his inconsistent responses to sound since he was 7 months of age. They noticed that when Matt and his cousin were together, the two children responded differently to sound. His cousin, who was 1 month older, was highly attentive to voices and environmental sounds. Matt was inattentive and sometimes required touch to get his attention. He did not use his voice when playing and did not favor toys that made noise.

Matt’s pediatrician was not concerned at this time and ascribed Matt’s differences with his cousin as age related and as two children reacting to sounds differently. She cited Matt’s history of several upper respiratory infections and the fact that he responded to voice when his back was turned. She doubted that an accurate test could be carried out at this age. A friend suggested that the parents seek out a pediatric audiologist.

Assessment

The purpose of Matt’s visit to the audiology clinic was to address parental concerns regarding whether any auditory problem existed, to evaluate his hearing sensitivity, and, if a loss was present, to develop a management plan. The initial clinical decision was the formulation of an overall strategy to assess Matt’s hearing. Based on an interview with Matt’s parents and an informal observation of him in the waiting room, the clinicians planned a behavioral approach to assessment. Matt’s age, appropriate developmental landmarks, and good vision made VRA the logical choice. (Behavioral assessment is the approach of choice, when possible, because it is the most direct measure of hearing.)

Using insert earphones, Matt conditioned easily to the VRA protocol. Consistent, head-turn responses were observed for the frequencies 500 through 8,000 Hz. Matt’s minimum response levels (MRLs) showed a mild hearing loss at 500 Hz, sloping to a severe loss at 4,000 and 8,000 Hz in each ear. (The term minimum response level is used in lieu of the common audiological term threshold when describing the responses of infants and toddlers.) Using speech, Matt responded to his name to both left and right ears at levels consistent with his pure tone responses. When testing by air conduction was finished, a bone conduction oscillator was placed behind Matt’s ear on his mastoid and bone conduction MRLs were determined. These results were found to be equal to the air conduction scores. Tympanometry showed normal middle-ear function in each ear. TEOAEs showed reproducible emissions at below 750 Hz but no emissions above this frequency. These findings combined to indicate that the loss observed by air conduction was sensorineural in nature (i.e., it originated in the cochlea or VIIIth nerve).

Recommendations

Matt’s parents were counseled regarding the extent of his hearing loss. They were told that his hearing loss ranged from mild in the low frequencies (with which he could easily detect their voices) to severe in the high frequencies (with which he would most certainly miss important aspects of speech). Because Matt heard the same through air and bone conduction presentations of sound, his hearing impairment was described to them as sensorineural and permanent in nature. The range of options for initial management and intervention were also presented so that the family could make an informed choice. A referral for genetic counseling was made to help the family answer questions about the etiology of the loss. A medical workup with an otolaryngologist was scheduled to rule out any medical contraindication to proceeding with hearing aids. Matt was fitted with binaural hearing aids and his parents enrolled him in a total-communication early intervention program for infants and children with hearing loss and their families.


References

American Speech-Language-Hearing Association. (1994). Joint Committee on Infant Hearing 1994 position statement. Asha, 36, 38–41.