redirect the audio output to /dev/null

I'm using an text-to-speech synthesis in a script, and I need to redirect it's output to /dev/null

how can I do that ? And how to redirect the stream to his normal output then sound card ) ?

thankx

Usually the shell doesn't have much control over audio. How to do that for your program depends on how it uses audio, etc.

What's the program?

the program is ekho, it s a free tts , it s in debian and ubuntu repository