Objective and subjective outcomes from Bone Conduction Hearing Devices

Abstract

Bone conduction hearing devices are generally the best treatment for patients whit a conductive or mixed hearing loss, or a single sided deafness, that cannot use conventional hearing aids. The aim of this thesis was to explores patients audibility and experiences of using an active transcutaneous bone conduction device and also to develop a new method for objective verification of audibility in patients using bone conduction devices. In study I, the result from the three-year follow-up shows that the BCI generally have the same or better improvement of audiological measurements compared to the reference device (Ponto Pro Power on softband) over the unaided situation. In both audiological measurement and quality of life questionnaire the BCI and the reference device showed a significantly better results, compared to the unaided situation. The nasal sound pressure measurements were stable over time and the there were no adverse skin complications due to the magnetic force. Study II and III contains results from the development and testing of a new method to objectively measure audibility with a skin microphone, placed in the forehead. The results show that the method can be used to measure audibility and used for adjustment for patients with different type of bene conduction devices. For Study IV, a qualitative approach was used to get a deeper understanding of patients experiences of using and living with the BCI. The data collection consisted of interviews and was then analyzed according to the phenomenographic approach. The data collection consisted of in-depth interviews which were analyzed according to the phenomenographic approach. The results from the analysis resulted in four different themes which were further represented through three or four categories. The overall results showed that the BCI can be an effective and safe treatment for patients with conductive or mild-to moderate mixed hearing loss and in interviews the BCI users state that the audio processor is easy to use and handle. The new method, using a skin microphone can be used to measure the individual dynamic range and the individual audibility in patients using bone conduction devices. The skin microphone can also be used to detect and improve a poor fitting.