A comparison of three approaches to verifying aided Baha output

Abstract

Objective: The objective of the present study was to compare three methods of estimating the audibility of aided speech using the Baha.

Subjects: 23 Adult Baha users with primarily bilateral conductive hearing loss were recruited from the Bone Conduction Amplification Program at the Institute for Reconstructive Sciences in Medicine in Edmonton, Alberta, Canada.

Methods: A test Baha was set to each subject's preferred listening level. The same Baha was used to assess the audibility of the long-term average speech spectrum (LTASS) for each of the following three approaches: 1) Aided soundfield thresholds, 2) Real Ear SPL, and 3) Real Head Acceleration Level.

Results: Significant differences were discovered between the three approaches. Aided soundfield thresholds consistently over-estimated the sensation level of aided speech. The Real Ear SPL approach provided reasonable estimates in the mid-frequencies. However, low- and high-frequency estimates for the Real Ear approach have significant limitations.

Conclusions: The Real Head Acceleration Level appears to be the most accurate method of determining aided audibility with the Baha.