title: Auditory brainstem responses to bone-conducted brief tones in young children with conductive or sensorineural hearing loss.
abstract: The bone-conduction (BC) tone ABR has been used clinically for over 20 years. The current study formally evaluated the test performance of the BC tone-evoked ABR in infants with hearing loss. Method. By comparing BC-ABR results to follow-up behavioural results, this study addressed two questions: (i) whether the BC tone ABR was successful in differentiating children with conductive versus sensorineural hearing loss (Study A; conductive: 68 ears; SNHL: 129 ears) and (ii) the relationship between BC ABR and behavioural hearing loss severity (Study B: 2000 Hz: 104 ears; 500 Hz: 47 ears). Results. Results demonstrate that the "normal" BC-ABR levels accurately differentiated normal versus elevated cochlear sensitivity (accuracy: 98% for 2000 Hz; 98% for 500 Hz). A subset of infants in Study A with elevated BC-ABR (i.e., no response at normal level) had additional testing at higher intensities, which allowed for categorization of the degree of cochlear impairment. Study B results indicate that the BC ABR accurately categorizes the degree of cochlear hearing loss for 2000 Hz (accuracy = 95.2%). A preliminary dBnHL-to-dBHL correction factor of "0 dB" was determined for 2000 Hz BC ABR. Conclusions. These findings further support the use of BC tone ABR for diagnostic ABR testing.
authors.affiliation: School of Audiology and Speech Sciences, The University of British Columbia, Vancouver, BC, Canada V6T 1Z3 ; Audiology Department, Britsh Columbia's Children' Hospital, Vancouver, BC, Canada V6H 3V4 ; British Columbia Early Hearing Program, Provicial Health Services Authority Victoria, BC, Canada V8V 3K3.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Hatton
authors.forename: Renée M
authors.initials: RM
authors.lastname: Janssen
authors.forename: David R
authors.initials: DR
authors.lastname: Stapells