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Audio Quality Terminology

ABSTRACT

The terms described herein relate to audio quality artifacts. The intent of this document is to

ensure Avaya customers, business partners and services teams engage in effective

communication involving audio quality related issues.

Summary of content (6 pages)

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Audio Quality Terminology ABSTRACT The terms described herein relate to audio quality artifacts. The intent of this document is to ensure Avaya customers, business partners and services teams engage in effective communication involving audio quality related issues. ©2005 Avaya Inc. All Rights Reserved.
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1 Introduction This document defines a variety of terms used to describe voice-related artifacts experienced in telephony. It is expected that this terminology will be used primarily by Avaya business partners and Avaya Global Services teams to facilitate the interpretation and understanding of voicerelated problems experienced in the field.
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2.1.3 Echo suppressor: like echo canceler, above, except the echo level is reduced or eliminated by applying suppression or attenuation to the return speech channel. The use of attenuation causes other audio artifacts, including chopping or clipping of speech utterances and/or pumping of the loudness level of a caller’s speech. 2.1.
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3.1.4 Synthetic, Mechanical, or Robotic Voice: this can be very subtle or very severe, or very consistent or intermittent. In the most severe case, the pitch information has been lost making the speech sound monotonic and robotic. Recognizing who is speaking is often difficult. 3.1.5 Amplitude clipping: see definition for distortion above. 3.1.6 Clipping: portions of the speech signal are not heard.
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and ruin the music signal or non-speech signal. This can be subtle or severe depending on the music source. 3.3 Echo There are only two physical sources of echo in telephony: electrical echo (or network echo), and acoustic echo. Electrical echo is caused by a reflection of the speech signal at 2-to-4-wire hybrid circuitry. This circuitry is present in analog trunk cards, and it also exists deep within the PSTN (at customer premises, for example).
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speakerphones and newer-model acoustic-echo canceling speakerphones. For example, a talker speaking into a handset utters the phrase “Please send me the check” and perceives echo primarily at the end of his/her sentence. This echo is described as hearing just the sound “eck” or “k” of the word “check,” or as a slapping sound such as that made by slapping one’s palm against a desktop. Commonly, slapback/kickback echo is caused by acoustically reverberant rooms.