In-Ear Microphone Equalization Exploiting an Active Noise Control

Document type: Conference Papers
Peer reviewed: Yes
Full text:
Author(s): Nils Westerlund, Mattias Dahl, Ingvar Claesson
Title: In-Ear Microphone Equalization Exploiting an Active Noise Control
Conference name: Internoise2001
Year: 2001
City: The Hague
Organization: Blekinge Institute of Technology
Department: Department of Telecommunications and Signal Processing (Institutionen för telekommunikation och signalbehandling)
Department of Telecommunications and Signal Processing S-372 25 Ronneby
+46 455 38 50 00
Language: English
Abstract: A pair of ear-muffs that employs active noise control(ANC) for noise reduction, substantially reduces the influence of the low frequencies inside the cap. This implies an indirect high-pass filtering of the sound in the external auditory canal (EAC). This paper shows that the above mentioned high-pass filtering property is convenient when combining an ANC headset with an in-ear microphone (ear-mic) for communication purposes since the speech signal inside the EAC is a low-pass filtered version of the speech signal at the mouth. Hence, the in-ear speech signal is to some extent restored by the ANC high-pass filtering, the quality of the speech signal in the auditory canal is improved and the speech intelligibility is increased. The equalization will also decrease the demand of dynamic range and resolution of electronics used. By that, combining an active ear-muff with an ear-mic serves two purposes: Protecting the user from harmful noise and enables the user to communicate over some channel using the speech signal in the auditory canal.
Subject: Signal Processing\Speech Enhancement
Keywords: Speech enhancement, Active Noise Control, Ear-muffs, channel equalizer
Edit