Factory fitted telephone support

If anyone has factory fitted phone support could you let me know if - when on a call does the DSP on the radio automatically switch to the "Talk" setting.

I've just installed a parrot kit thru the tele-in connection on a Rhapsody radio. The sound is generally ok, but improves a lot when the DSP is set to "talk". However for some reason the DSP setting when on "phone" does not hold and so I have to turn on the "talk" DSP setting for each individual call.

Double Din Rhapsody radio in a 06 Superb Elegence.