Barham, R G; Rasmussen, K*; Fedtke, T*; Rodrigues, D*; Zmierczak, T* (2008) Measurement of the acoustical impedance of artificial ears. A report on EURAMET Project 791. NPL Report. AC 6

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Abstract

Ear simulators are measuring instruments for the objective evaluation of the acoustical performance of earphones and other devices designed to be coupled acoustically to human ears. A device, often referred to as the artificial ear, is used widely in audiometry, telecommunications and audio engineering, and its specification is given in IEC 60318-1. This document is currently under revision by IEC to include: an extension of the frequency range to 16 kHz, assimilation of the scope of IEC 61318-2 for the measurement of circumaural headphones, and most significantly, a method for determining the acoustical impedance. This report describes collaborative research that has been conducted by five European National Metrology Institutes to establish a new measurement method. This method has been used to produce normative data for the acoustical transfer impedance as well as the corresponding measurement uncertainty. The report then recommends a new specification for the impedance and its tolerance, as well as consequential changes to the associated lumped parameter model.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	AC 6
Subjects:	Acoustics Acoustics > Sound in Air
Last Modified:	02 Feb 2018 13:15
URI:	https://eprintspublications.npl.co.uk/id/eprint/4180