A New Passive/Active Hybrid Headset for a Helicopter Application

Document type: Conference Papers
Peer reviewed: Yes
Author(s): Sven Johansson, Mathias Winberg, Ingvar Claesson
Title: A New Passive/Active Hybrid Headset for a Helicopter Application
Conference name: RadioVetenskap och Kommunikation 99 (RVK99)
Year: 1999
Pagination: paper no: RVK006
ISBN: 91-630-8156-3
Publisher: Högskolan i Karlskrona/Ronneby
City: Karlskrona, Sweden
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
Authors e-mail: sven.johansson@bth.se
Language: English
Abstract: In helicopters, the low frequency noise generated by the rotors and engines
often masks and jeopardizes safe communication. In addition, pilots are
likely to suffer from damage to their hearing due to the high sound levels in the headset produced in compensating for the noise caused by increased loudspeaker levels. A feasible approach is to reduce the low frequency noise by using active techniques combined with a method for reducing the noise in the intercom microphone signal, with lower loudspeaker levels as a result. In order to achieve an efficient attenuation of the primary noise inside the headset, a combination of a digital feedforward controller and an analog feedback controller is employed. Spectral Subtraction is used to suppress the background noise in speech signals. This paper evaluates a combination
of the techniques and their application to real data.
Subject: Signal Processing\Active Noise and Vibration Control
Keywords: active noise control, speech enhancement, headset