swirec_waveform_end_silence

How much silence is kept in a collected utterance.

Value

Integer: 0–INT_MAX.

Default

0 (milliseconds)

How to set

Shown in precedence order (see Rules of parameter precedence):

Set in the browser, using the Vendor-Specific-Parameters header in a RECOGNIZE or SET-PARAMS method.

In a parameter grammar.

In Management Station set on the Nuance recognition service. If not using Management Station, set in a Recognizer configuration file (User-nrsxx.xml).

Usage

Occasionally used for whisper-transfer applications to remove unnecessary silence in captured audio recordings.

Performance

Removing silence shortens the playback time needed to play the audio waveform to a human administrator, but removing too much silence can make the waveform incomprehensible to the administrator.

Use this parameter when implementing whisper transfer features (also known as store-and-forward) where audio recordings are captured and then played to human agents. It specifies the duration of trailing silence (after the end-of-speech) in the returned waveform.

This parameter has no effect unless SWIrecGetWaveform suppresses silence at the end of the audio recording.

This parameter is intended to reduce silence, but it can also increase silence at the end of the waveform. If the amount of silence at the end of the endpointed waveform is less than the value of swirec_waveform_end_silence, then the end of the returned waveform will be padded with digital silence (linear 0) to satisfy the specified value.

Browsers usually set this parameter in a RECOGNIZE request, and the parameter automatically reverts to the previous value after the recognition event. (Alternatively, browsers can use the SET-PARAMS method. See Configuring Recognizer with the browser.)

Vendor-Specific-Parameters: swirec_waveform_end_silence=100

Related parameters