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 ?
38 real-time fax relaying for VoIP equipment interoperability, voice activity detection for silence compression, comfort noise generation for a more natural speaking experience, and 5.
The algorithms may, in the event of packet loss, replay the last packet, insert comfort noise, interpolate, etc.
When integrated with D2's vPort GW software platform, the RT3050, RT3350 and RT3052 provide advanced VoIP functionality including an application layer, a SIP protocol signaling module, advanced voice quality assurance technology such as jitter buffer and packet loss compensation, telephony drivers, and a softDSP "voice engine" with all the necessary DSP algorithms for voice compression, echo cancellation, tone detection/generation, comfort noise generation, caller ID, FAX relay, and more.
The sound quality is exceptional thanks to Comfort Noise Generation, Voice Activity Detection and Echo Cancellation.
729 but requires less computation, and G729B, which is a silence compression scheme with Discontinuous Transmission (DTX), Voice Activity Detection (VAD), Comfort Noise Generator (CNG) and Silence Insertion Descriptor (SID).
The solution integrates features such as Unicoi's family of voice codecs, acoustic (AEC) and line echo cancellation (LEC) software, a dynamic jitter buffer, Voice Activity Detection (VAD), Comfort Noise Generation (CNG), three-way conferencing and SIP based call processing.
Additional sound enhancement features are integrated for optimizing sound quality such as the 10-band graphic equalizers and spectrally matched comfort noise.
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.