Voice Activity Detection / Comfort Noise Generation
VAD determines whether or not speech is present in the outbound signal, CNG generates a noise signal at the level sent from the transmit side.

VAD/CNG

The VAD determines whether or not speech is present in the outbound signal, when speech is not present, the CNG algorithm generates a "comfort" noise signal.

FEATURES

  1. Functions are C-callable.
  2. Multi-channel capable
  3. Can be used with all types of speech coding
  4. Spectrally shaped noise generation

ADT VAD / CNG is available on the following Platforms: Other configurations are available upon request.

Platform
Cortex-M3
Cortex-M4
Cortex-A8
Cortex-A9
Cortex-A15
ARM9E / ARM11

DESCRIPTION

Adaptive Digital’s VAD/CNG software performs voice activity detection and comfort noise generation. It is used in systems that used reduced bandwidth channels during silent or non-voiced portions of a conversation. The VAD algorithm is used at the transmit side of a communication link. The VAD determines whether or not speech is present in the outbound signal. If speech is not present, the VAD algorithm determines the level of the background noise. The background noise level is transmitted to the opposite end of the link in place of the speech signal. The noise level requires little channel bandwidth and only needs to be transmitted when the background noise level changes. The CNG algorithm runs at the receive side of the link. When speech is not present, the CNG algorithm generates a noise signal at the level sent from the transmit side.

Applications include Voice-Over-Packet, Satellite, and other digital voice applications.

SPECIFICATIONS


ARM® DEVICES

VAD/CNG ARM Cortex-A8/A9/A15

CPU UTILIZATION & MEMORY REQUIREMENTS
All Memory usage is given in units of 16-bit word.
SOFTWARE MIPs (Peak) Program Memory Data Memory Per-Channel Data Memory Scratch Memory
VAD 0.26 4K 336 80 0
CNG 1.3 0


VAD/CNG ARM Cortex-M3/M4

CPU UTILIZATION & MEMORY REQUIREMENTS
All Memory usage is given in units of 16-bit word.
SOFTWARE MIPs (Peak) Program Memory Data Memory Per-Channel Data Memory Scratch Memory
VAD ?? ? ? 80 0
CNG ?? 0
Contact Sales for specifications: 610-825-0182 x120

VAD/CNG ARM9E / ARM11

CPU UTILIZATION & MEMORY REQUIREMENTS
All Memory usage is given in units of 16-bit word.
SOFTWARE MIPs (Peak) Program Memory Data Memory Per-Channel Data Memory Scratch Memory
VAD 0.22 4K 336 80 0
CNG 1.22 0

 

We specify MIPS (Millions of Instructions per Second) as MCPS (Millions of Instruction Cycles per Second). Unless otherwise specified, peak MIPS are indicated.

FUNCTION

VAD_ADT_vadInitialize (…) Initializes the VAD and CNG modules
VAD_ADT_vad (…) Executes voice activity detector
CNG_ADT_cng (…) Executes comfort noise generator

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arm Voice Activity Detection/Comfort Noise Generation for ARM

 

VAD / CNG is used
in systems that used reduced bandwidth channels during silent or non-voiced
portions of a conversation.

Contact us
  for more information