Setting up Scenes

The AMLTTP is capable of generating auditory scenes under various conditions. The generation is performed by the Binaural simulator. The AMLTTP takes care of setting up the simulator and driving it to produce scenes under specific and various conditions using a dataset of sound files.

A scene is configured by specifying: * The room * Individual sound sources * The SNRs of the sound sources relative to the first sound source * Charactersitics of the virtual head in the room (e.g. orientation) * The duration of the sounds

This instantiates a scene configuration:

sc = SceneConfig.SceneConfiguration();

By default the scene is configured so that sound sources are positioned at 0° azimuth relative to the head. There is no interfering noise, and no reverberation (i.e. free-field conditions).

Adding a sound source to the scene involves calling addSource method and passing it SourceBase object. Available source types include: * PointSource for directional sounds * BRIRsource for directional sounds with reverberations * DiffuseSource for non-directional ambient sounds

sc.addSource( SceneConfig.PointSource( ...
     'data', SceneConfig.FileListValGen( 'pipeInput' ) ) );
Table 35 Key value pairs to pass to the source constructors common between all Source types:
Argument key Default value Description
data white noise at 44.1Khz source of the data to emit from this source
offset 0.5 sec offset at which to begin sounds
normalize true whether to normalize the sound emitted or not
normalizeLevel 1.0 Normalization level

Point Source

Constructing a source for emitting directional sounds in free-field conditions.

Table 36 key value pairs for a point source in addition to the specifications that are common for all source types:
Argument key Default value Description
azimuth 0^{o} angle between source and nose
distance distance from the listener 3 m

BRIR Source

Constructing a source for emitting directional sounds with reverb.

Table 37 key value pairs for a BRIR source in addition to the specifications that are common for all source types
Argument key Default value Description
speakerId None Id or index of the speaker in a room

Diffuse Source

Constructing a source for emitting non-directional ambient sounds in free-field conditions.