Using other text-to-speech engine

Question:

Why Voicent Gateway does not support other SAPI based text-to-speech engine?

Answer:

There are both technical and licensing issues:

1). Technically, a SAPI-based TTS engine can generate voice given a block of text. To use it over the telephone, you need additional functions from Voicent Gateway. These functions include dynamically manage TTS audio streams with pre-recorded audio streams; serve the TTS audio streams simultaneous to multiple channels (TTS engine server); caching TTS audios to reduce CPU usage, etc. All these functions are not part of the TTS engine.

This part of the TTS functionality, including the Paul & Kate voices, is an add-on product to Voicent Gateway. It is sold separately.

2). TTS engine and voices are normally priced according to whether it is a desktop version or server version. Most vendors, including Voicent, charge a lot more for server version than desktop version. We are not selling the desktop TTS engine as a separate product. Since without the server functionalities, this TTS engine cannot be used to make phone calls.

3). Licensing wise, some big name vendors specifically prevent us from enabling their TTS engines. So if a Voicent customer buys their TTS engine through other companies, we are not allowed to enable it. In order to enable their TTS engines, we have to license their server version, which costs a lot more than Voicent TTS engine for telephone.

4). You can use your existing TTS engine to generate an audio file. Then use that audio file to play over the phone. But you will not be able to dynamically generate the audio using other TTS engines.