Accuracy and precision of direct bone conduction measurements
A. M. Sadeghi , M. Flynn , T. Davison , M Schulte and M. Hillbratt 3 1
2Department of Audiology, The Sahlgrenska Academy, Institute of Neuroscience and Physiology, Göteborg, Swe3en; Department of Audiology, Hearing activities organization, Habilitation & Health, Göteborg, Sweden; Department of Research and Applications, Cochlear Bone Anchored Solutions AB, Mölnlycke, Sweden; 4Department of Audiology, Freeman Hospital, Newcastle, United Kingdom; Hörzentrum Oldenburg GmbH, Oldenburg, Germany
Bone anchored hearing aid; bone conduction; direct bone conduction; single-sided deafness; hearing implant; mixed hearing loss
41 - 51
Accuracy and precision of direct bone conduction measurements. Objectives: Variability in Baha sound processor fittings arise from several sources including the nature of the implant-to-bone transmission and transcranial attenuation in patients with single-sided sensorineural deafness. One method of improving the predictability of Baha fittings is to measure the individual patients actual bone conduction thresholds via the implant, thereby removing the influence of skin thickness and/or implant location site. Methodology:One hundred thirty eight adult wearers of the Baha System participated in the study. Direct bone conduction thresholds were obtained through the BC Direct feature of the Cochlear Baha Fitting Software combined with the CochlearBaha BP100 sound processor. Test-retest reliability measurement was performed in 58 participants. Results:Improvedtransmissionofsoundthroughtheimplantratherthantranscutaneouslythroughtheskinwasconfirmed. On average, the BC Direct thresholds were closer to the patients unmasked thresholds than the masked values. In patients with single-sided sensorineural deafness, BC Direct results were elevated compared to the contralateral bone conduction thresholds due to transcranial attenuation. The test-retest reliability for the BC Direct measurements was within ±5 dB, which is in within the accepted variability for audiometric test measurements. Conclusions: Direct bone conduction measurement provides a validated method of comparing the transcutaneous thresholds as measured through audiometry with the percutaneous responses from the Baha sound processor. The Baha fitting based on direct measurements of bone conduction may require less fine-tuning and provide a greater understanding of the variability of the bone conduction sound pathway.
Vol. 12, 2016, 1st trimester

Accuracy and precision of direct bone conduction measurements