* structures. If the freq0 variable is non-zero, the tone table contents
* for the tone_index are updated to the frequencies and gains defined. It
* should be noted that DTMF tones cannot be reassigned, so if DTMF tone
* structures. If the freq0 variable is non-zero, the tone table contents
* for the tone_index are updated to the frequencies and gains defined. It
* should be noted that DTMF tones cannot be reassigned, so if DTMF tone