ZDO Corporation - Telephony

Talker Echo Loudness Rating

nospam@example.com (Onur Cinar) — Mon, 01 Jan 2007 00:00:00 -0700

Talker Echo Loudness Rating (TELR) is total echo loss from receiver to sender.
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Packet Loss Concealment

nospam@example.com (Onur Cinar) — Mon, 01 Jan 2007 00:00:00 -0700

If speech information is lost, it is impractical to try to retrieve it. Packet Loss Concealment (PLC) generates synthetic speech to cover the missing data.

For CELP based codecs, such as G.729, it is relatively easy since the speech is modeled during encoding phase. It is more difficult with waveform codecs, such as G.711.

However, waveform codecs can recover from packet loss more rapidly since the first speech sample in first good packet restores the speech to original.

E-Model

nospam@example.com (Onur Cinar) — Thu, 01 Jan 2004 00:00:00 -0700

E-Model is a planing tool for estimating the overall quality in a telephone network. It is an ITU-T strandard.
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Pulse Code Modulation

nospam@example.com (Onur Cinar) — Thu, 01 Jan 2004 00:00:00 -0700

Pulse Code Modulation (PCM) is a digital representation of analog signal.
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