Active Hearing Protection Systems and Their Performance
Abstract
The present paper gives a brief history of active noise cancellation. It shows that the possibility of using ANR in hearing protection devices was proposed long before the first commercial devices became known. The basic theory of active noise cancellation is quite simple and was first described in the 1930 s. The basic principles and the different approaches to obtain active noise cancellation are described in this paper. Different ANR techniques are presented (feed-forward, feedback) as well as different possibilities for their implementation (analog and/or digital). The possibility for optimum insertion of a communication signal into an ANR hearing protector is described. The impact of ANR protectors on the noise exposure and on the speech intelligibility is discussed. Critical parameters like stability and overload are discussed and some basic design rules will be shown. The problems arising during an implementation earplugs will finally be discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2005
- Accession Number
- ADA444679
Entities
People
- K. Buck
- V. Zimpfer-jost
Organizations
- Air Force Research Laboratory