Complete Communications Engineering

Have you ever been on an important phone call and suddenly the background noise of the space you are in becomes significantly louder? Of course, then you are left trying to find a quiet place or fumbling over the volume controls on your phone. VOCAL’s Automatic Volume Control (AVC) is a valuable solution to improve the usability and intelligibility of your telecommunications product. This software can be included as part of VOCAL’s Voice Quality Enhancement (VQE) package and VoIP stack.

Automatic Volume Control requires a microphone signal to estimate the noise characteristics of the acoustic environment. From this information, the AVC software applies a frequency dependent amplitude modification to the received signal prior to being sent to the loudspeaker. The volume modification is frequency dependent because the response to tonal noise should be different than the response to broadband noise. For optimal performance, the AVC must engage in a short learning phase, to obtain the electrical noise characteristics of the microphone and ADC components, so those noise components are not conflated with the acoustic environment noise.

automatic volume control

AVC can be applied to half-duplex and full-duplex applications. Full-duplex applications already require Acoustic Echo Cancellation (AEC) software, but for half-duplex applications AEC is required for proper operation of the AVC software. The signal being played out of the loudspeaker must not interpreted as acoustic noise.

VOCAL’s Automatic Volume Control software is efficiently integrated into VOCAL’s AEC module, and Voice Quality Enhancement package. Please contact us to learn more how our VQE solutions can be applied to your product design.