ITU-T P.570 PDF

The quality of ambient noise transmission is an important factor, which significantly contributes to the perceived overall quality of speech. Existing and even more the new generation of terminals, networks and system configurations including broadband services can be greatly improved with a proper design of terminals and systems in the presence of ambient noise.

This Recommendation:

– provides information about techniques needed for capturing real-world noise environments;

– outlines methods for preprocessing of signals for artificial noise fields (ANFs);

– specifies loudspeaker set-ups and a loudspeaker calibration procedure;

– describes the requirements for laboratory conditions;

– specifies techniques for assessing ANFs.

The ANF established when applying this Recommendation can be used for the evaluation and optimization of terminals and of complex configurations including terminals, networks and other configurations.

The ANF described in this Recommendation is applicable to:

– objective performance evaluation of terminals in different ambient noise environments;

– speech-processing evaluation by using the preprocessed speech signal in the presence of ambient noise, recorded by a terminal;

– subjective evaluation of terminals by performing conversational tests, specific double talk tests or talking and listening tests in the presence of ambient noise;

– subjective evaluation in third party listening tests by recording the speech samples of terminals in the presence of ambient noise.