Text-to-Speech/Audio Prompt
There are two types of prompts in VoiceXML:
- Prompt using text-to-speech
- Prompt using pre-recorded audio message
The message between <block> and </block> in our timeofday
example is the first type. The gateway reads in the text and
automatically converts it to speech and plays it over the phone.
It is usually nice to have a pre-recorded audio message if the
message does not change. The rest of this section shows how to do
this.
Please note that the voice generated by the default Microsoft
TTS engine is robotic and very hard to understand. You should use
Voicent Natural Text-to-Speech engine for commercial use.
1. Record and save an audio file
Use any recording tool, such as the Sound Recorder, to
record your message. Make sure to save it using the correct audio
format suitable for telephone. Voicent Gateway only supports "PCM
8 KHz, 16 bit, mono" wave format.
Create a sub-directory under <tddir>/webapps/audio, and
save your recording as welcome.wav.
For commercial products, it is strongly
recommended that you use professional recording studio to create
your audio prompts. The sound quality recorded by a regular
computer microphone is usually poor, as you can tell from the wave
files included in the sample code.
2. Change your vxml file
- <?xml
version="1.0"?>
<vxml version="1.0">
- <form
id="td">
<block>
<audio src="audio/welcome.wav"/>
</block>
</form>
- </vxml>
3. Call in to check your new timeofday service
Now instead of hearing the text-to-speech voice, you should
hear your own recording.
Download the sample code:
timeofday_step2.zip.
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