Noise Canceling Headsets for Speech Communication
Headsets for speech communication are used in a wide range of applications. A communication headset usually consists of a pair of headphones and a microphone attached to the headset with an adjustable boom. This chapter focuses on passive and active control of the noise inside the ear cups of headsets. It also focuses on two techniques for reducing the amount of background noise picked up by the intercom microphone and transmitted with the speech: spectral subtraction and a new in-ear technique. Analog feedback active noise control techniques for use in headset applications have received considerable attention. These techniques have proved to be very successful at improving attenuation at frequencies below 1000 Hz by up to 20 dB and at the same time enabling comfortable noise canceling headsets to be designed. For the control of narrowband noise both digital feedback and digital feedforward controllers enable further attenuation to be achieved compared with analog feedback controllers.