Measurement of the acoustical impedance of artificial ears

Project Description

The ear simulator specified in IEC 60318-1 (known also as the artificial ear) is designed to present an earphone with the same acoustic impedance as an average human ear. While the current version of the standard provides data on the required acoustic impedance, it does not specify tolerances or a measurement method, making it impossible for this parameter to be verified by test laboratories. IEC 60318-1 is being revised to include these elements. It therefore needs input from a number of laboratories on two aspects:

• evaluation of the proposed measurement procedure and investigation of a number of issues that will help refine the method.
• collection of data on the acoustical impedance of a number of devices that will form part of the sample that defines the data to appear in the revised standard
   

A collaborative research project will therefore be formulated to address these two points. The output from the project will feed directly into the revision process for IEC 60318-1 which is already underway.

There may be additional contribution on this topic from IEC TC29 WG21.
The project was agreed at the TC-AUV meeting in May-04, Vienna.

Final Report 2008-07-03

A final report NPL AC 9 has been published and is available from the pilot laboratory (NPL).

Progress Report 2005-08-12

A project protocol was discussed at the sound-in-air SC meeting in Torino, May-05. The protocol was approved and a revised timescale agreed.