Using the Speak Text Action
Once method of employing TTS is through adding a Speak Text action to a call flow. The text to be spoken is entered in the action's Specific tab. This text can include combinations of:
TTS SAPI Controls
Windows TTS engines use Microsoft's SAPI (Speech Application Program Interface). This includes the use of XML tags within the text to change how the text is spoken.
For example in the text This is the <volume level="90">text</volume> to speak the items within < > brackets are XML tags used to alter how the speech is spoken.
The following are a sample of the SAPI XML controls supported by Voicemail Pro TTS. Further information on SAPI 5 can be obtained from Microsoft's support websites.
Volume - Alter the speech volume.
Rate - Alter the speech rate.
Pitch - Alter the speech pitch.
Emph - Add emphasis to words.
Spell - Spell out words and numbers literally.
Silence - Add a period of silence.
Partofsp - Change a words usage.
Entering XML Tags
XML tags can be used in two ways, either "nested" or "empty".
Example SAPI XML Tags
Controls the volume of the speech. This tag can be nested or empty.
Controls the speed at which the text is spoken. This tag can be empty or nested.
Controls the pitch at which the text is spoken. This tag can be empty or nested.
Applies emphasis to a word or section of text. This tag must be nested.
Spell forces the engine to speak any nested text literally rather than applying any speech rules. This is useful for numbers where rather that than saying 3001 as three thousand and one for 3001, the speech required is three zero zero one. This tag must be nested.
Inserts a period of silence. This tag must be empty.
Forces the pronunciation of a word according to it usage if not correctly determined by the TTS speech engine or to override the engine. This tag must be nested.