[. . . ] Advanced Perceptual ECHO Measurement Tool OPTICOM's Advanced ECHO measurement tool provides accurate and repeatable estimates of multiple audio signal echoes in a telephony network. [. . . ] Another advantageous side effect is that through the speech signal's natural modulation a best match of the two correlated signals can be found with higher accuracy than with sine tones. Therefore the results become more robust against clipping and noise. PEVQTM, 3SQMTM and the OPTICOM logo are registered trademarks of OPTICOM GmbH; the `single-sided speech quality measure' and `the perceptual quality experts' are trademarks of OPTICOM GmbH. All brand and product names are trademarks and/or registered trademarks of their respective owners. Copyright © 2005 OPTICOM GmbH ­ www. opticom. de The diagram below gives you an example of the results of a typical measurement with OPTICOM's ECHO tool after the data was evaluated with a spread-sheet program. The diagram is divided into two distinct areas separated by an extrapolated and approximated talker echo tolerance curve derived from the ITU-T standard G. 131. All echoes (peaks) that do not reach out of the blue area are generally likely to be perceived as annoying while all peaks that reach into the orange area are sufficiently attenuated and are tolerable ­ if perceived at all. Here, easily three echo peaks can be identified which lie in the blue area of the diagram. These echoes are too loud to be negligible and are very likely to be perceived as annoying by a customer. About OPTICOM With PSQM, PESQ and PEAQ, OPTICOM GmbH, the pioneer in perceptual quality testing has been providing three international world-class standards for voice and audio quality measurement since its foundation in 1995. [. . . ] All brand and product names are trademarks and/or registered trademarks of their respective owners. [. . . ]