Related links

Search Site


AVQ - Automatic Volume and eQualization control

You are here: Technologies -> AVQ

About AVQ

Comfortable reproduction of music or speech in conditions with varying ambient noises requires constant changes in sound level (with changes in noise level) and equalization (with changes in noise spectrum). For example, volume and equalization set for a standing car will not be adequate when the car is moving. In its turn, adjusted for moving car conditions, the sound may again become unintelligible when air-conditioning is switched on or windows are open. Today, the user has to change the sound volume manually which is uncomfortable and, in some cases such as a hands-free car kit, even dangerous. Suitable manual frequency equalization is almost never possible due to a large number of parameters to be controlled “on the fly”.

Automatic Volume and Equalization control (AVQ) technology amplifies and equalizes sounds according to ambient noise characteristics providing equal perceptual loudness, intelligibility and sound coloration in conditions where noise level and spectrum are changing dynamically. The technology is suitable for both speech and music. It significantly improves user experience in such applications as mobile phones, hands-free car kits, Bluetooth headsets, portable music players, car radios, and other mobile voice and audio applications.

Figure 1. AVQ principle of operation

A microphone (already present in communication devices) is used to monitor the current noise conditions. The microphone signal is analyzed and the ambient noise parameters are extracted. Acoustic Echo Cancellation technology may be used to remove parts of the speaker signals present in the microphone signal due to acoustic coupling between the two. Simultaneously, the current signal parameters are analyzed and fed into the equalization block. This block dynamically amplifies parts of the signal spectrum masked by noise ensuring equal intolerability an perceptual loudness in variable noise condition.

Figure 2. Signal spectrums in different conditions

Interactive audio examples

Use control buttons on the interactive screenshots to play/stop/navigate.

Woman and man speech with background sounds, AVQ is off (no processing); volume and equalization are adjusted for quite conditions:

The same speech signal but processed with AVQ. Note that the background noise represents ambient noise in the device environment and can not be reduced using the device speaker:


AVQ and other technologies

Although it can be used standalone, Automatic Volume and Equalization control is also integrated with other Alango technologies into one Voice Communication Package (VCP). The package also includes acoustic echo cancellation, stationary and transient noise suppression, dynamic range compressor, speech enhancement, (optional) adaptive dual microphone and several others.

White papers

110th AES Convention paper >>
AVQ technology white paper >>

Additional information

AVQ leaflet >>

Please contact us for more information, audio examples and real time demo availabilities.



go back to the Technologies page.


(c) Alango Technologies Ltd., 2006-16

Site development:, 2006-8