volume

Specifies the speaking volume based on the Vocalizer volume scale.

Value

Integer: 0–100.

DEFAULT:

80 for Speech Server and Vocalizer

How to set

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

Set in the session xml file for the application. Configure the <speechsynth> element located under <sessionparameters>, <speechserver>.

Set in a VoiceXML application, using the volume attribute of a <prosody> element.

Set in a voice browser, using the Prosody-Volume header in a SPEAK method.

Usage

Frequently used.

Specifies the amplitude of TTS audio, where lower values are lower volume levels.

Vocalizer’s default volume level is set to maximize voice quality by using the full resolution of the PCM samples it produces, and often needs adjustment for the application specific deployment environment. The volume requirements vary widely across application environments, but for optimal audio quality it is generally better to adjust the volume as close to the playback device as possible when there is a choice between modifying the Vocalizer volume or modifying the volume elsewhere.

This value is overridden if the volume is set via the MRCP protocol, or markup.