Adjustable filtering structure design dedicated to a programmable hearing aid apparatus

International Journal of Physical Sciences

Mongi Lahiani¹ 

关键词: Programmable hearing aid;    Filter;    Amplifier;    Digital to Analogue Converter.;   

DOI  :  

学科分类：物理（综合）

来源: Academic Journals

【 摘 要 】

This research concerns the conception and the development of one specific circuit for a programmable hearing aid. In fact, actual hearing aid prosthesis should be flexible and programmable apparatus to the pathological case. First of all, it must be adjusted according to the pain threshold conserving all dynamics sound. Second, it must be adapted to different patient audiogram levels. In this article, we present the design of our conception using an adjustable amplifying chain formed by five analogue filters. In particular, such filters could be adjusted according to patient audiogram in order to compensate the considered hearing loss. Amplifier structure in this filters’ chain were independently controlled using current sources conceived by MOS transistors. At each amplifying structure, one could distinguish two stages referred as Amgand Amf: Amgwas conceived to control the filter’s gain where Amfwas conceived to control frequency band width. On the other hand, one MOS transistor current source was commanded by a Digital to Analogue Converter assuring then the possibility of programmability. The overall circuit was conceived using MOS technology in order to satisfy the low power incessant need for such biomedical applications.

【 授权许可】

CC BY