BAHA results in children at one year follow-up: a prospective longitudinal study

To evaluate audiometric and clinical results of children fitted with a bone-anchored hearing aid with specific emphasis on speech discrimination in different sound environments after one year of use.

We performed a prospective longitudinal study. Seventeen patients between the ages of 5 and 18 years old were included. All patients underwent a complete tonal and vocal evaluation at four pre-determined intervals between the pre-operative period and one-year of bone-anchored hearing aid (BAHA) use. Basic pure-tone average and speech reception threshold were measured in different sound environments. Speech discrimination improvement was tested with the voice originating from the side of the BAHA-fitted ear and with the voice originating from a source directly in front of the patient. These measures were repeated with confounding noise facing the patient then from the side of the affected ear. All tonal and vocal evaluations were performed pre-operatively, the day of processor insertion, 6 months and 12 months after processor insertion. A variance analysis was performed to compare differences in hearing gain with BAHA over time.

Hearing gain with BAHA was clinically and statistically significant at all intervals. Conventional tonal evaluation revealed significantly improved hearing gain after BAHA insertion compared with pre-operative testing with BAHA (26.3 dB vs. 17.3 dB), and this improvement was maintained at one year (27.9 dB). Speech discrimination gain at one year was better than immediately post-insertion (21.9% vs. 11.7%). Maximal gain with BAHA was found with the voice originating from the side of the affected ear and with confounding noise facing the patient (27.1% at one year), whereas the least gain was found in a silent room with the voice coming from straight ahead (11.9% at one year).

Pure-tone average gain at one year post-insertion was similar to immediate post-insertion gain. BAHA aids speech discrimination most when the voice originates from the side of the affected ear with confounding noise facing the patient. Speech discrimination gain improves with time, suggesting an underlying learning process. The best BAHA gain in speech discrimination occurred with background noise.