Patent ID: 9578432
Date: 2017-02-21
CPC Classifications: H04R

Claim:
1. A system for of evaluating performance of a portable device including at least a speaker, a reference microphone, and an error microphone, and an adaptive noise cancellation circuit having an anti-noise filter with a transfer function W(z), the tool system comprising: a testing apparatus measuring a secondary path transfer function S(z) representing the response of the electronic components in the portable device, and acoustic/electric transfer function of the speaker, including acoustical coupling between the speaker and the error microphone in a predetermined acoustical environment of the portable device, wherein the testing apparatus includes a pinna test dummy holding the portable device in a predetermined physical configuration to emulate the predetermined acoustical environment, and an application test board configured to accept the adaptive noise cancellation circuit, and wherein the testing apparatus determines a quality factor QF for a predetermined acoustical environment by measuring invertability of the transfer function W(z) relative to the secondary path transfer function S(z) as an indicia of performance of the secondary path of the portable device.