Sometimes, when using an analog telephone interface in a conferencing system, you may find that the Dial Tone and/or DTMF Tones are too loud compared to the normal call audio level. Since both types of tones are generated in the Receive block of the analog telephone interface, some simple logic and a Ducker can help to control the levels of these signals automatically.
Lowering Dial and DTMF tones
- Add a Ducker to your configuration file and insert it inline with the receive signal from the analog telephone interface.
- Add a 2-channel OR gate (a type of Logic Gate).
- Connect the "D" logic node on the Dialer block to one of the inputs of the OR gate. This logic connection allows us to control DTMF tones.
- Connect the "DTD" logic node on the Control/Status block to the other input of the OR gate. This logic connection allows us to control Dial tone.
- Double-click on the Ducker to open the control dialog.
- Enable the Logic In.
- Set the Ducking Level to the attenuation needed for Dial and DTMF Tones.