comfort noise


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comfort noise

A very low-volume tone injected into the receiving end of voice over IP (VoIP) communications to prevent the listener from thinking the line went dead. There was always a slight background noise in analog phone lines. However, digital methods have replaced analog, and without the comfort noise, the line can seem disconnected during pauses in conversation, or when someone is on hold (without music) or when the other party puts the phone down for a moment. See TDM-to-packet conversion.
References in periodicals archive ?
With burst loss, replaying the last packet several times would produce a stuttering or "rrrrrr" effect, or continuous insertion of comfort noise would produce extended silence, or frames of reference would be lost for interpolation.
Echo cancellation combined with voice activity detection and comfort noise generation supports guaranteed delivery of toll-quality voice to subscribers.
168-2002 echo cancellation (up to 128 msec), comfort noise generation (CNG) with level control, wireless codecs with Voice Quality Enhancements (VQE), voice data compression, PCM support, carrier-class diagnostics, fax relay and low system latency.
168-2000 Line Echo Canceller, Voice Activity Detection (VAD), Comfort Noise Generation (CNG), Jitter Buffer, Packet Loss Concealment (PLC), DTMF Tone Detection and Generation, Call Progressive Tone (CPT), SIP/RTP/RTCP Call Signaling and Control, and multi-channel system-level framework.
The card will transport channel associated signaling (CAS) over ATM and DSL, using silence suppression, comfort noise injection and echo cancellation technology features.
GIPS AEC delivers the highest possible voice quality with an adaptive filter, non-linear processor (NLP), comfort noise generator and control system.
Comfort noise generation with silence detection and compression allows for optimal use of channel bandwidth.
In addition to the high quality compression and echo cancellation, the Wireless Network Compression solution features silence suppression with superior Voice Activity Detection (VAD) and Comfort Noise Generation (CNG), and intelligent packet loss concealment (PLC) with low-delay and non-blocking.
By utilizing TI's voice-optimized DSPs and Telogy Software products, Alcatel's 7300 ASAM will support a broad set of carrier class features including tone detection and generation, voice activity detection, echo cancellation up to 128 msec, comfort noise generation and fax relay.
726 voice codecs, comfort noise generation, tone handling, acoustic echo cancellation, playback/record capabilities and 3-way audio conferencing support.