The quality of background 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 background noise. ETSI ES 202 396-1:

• describes a noise simulation environment using realistic background noise scenarios for laboratory use;
• contains a database including the relevant background noise samples for subjective and objective evaluation.

The present document provides information about the recording techniques needed for background noise recordings and discusses the advantages and drawbacks of existing methods. The present document describes the requirements for laboratory conditions. The loudspeaker setup and the loudspeaker calibration and equalization procedure are described. The simulation environment specified can be used for the evaluation and optimization of terminals and of complex configurations including terminals, networks and other configurations. The main application areas should be: office, home and car environment.

The setup and database as described in the present document are applicable for:

• Objective performance evaluation of terminals in different (simulated) background noise environments.
• Speech processing evaluation by using the pre-processed speech signal in the presence of background 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 background noise.
• Subjective evaluation in third party listening tests by recording the speech samples of terminals in the presence of background noise.