Can only hear/speak during a phone call when on speakerphone

[wibble]

If I understand it correctly the audio paths between transducers and modem don't pass the audio through the alsa interfaces, so we can't use software echo cancellation. The modem is supposed to include echo cancellation, but the information I've found in the AT command manual sections on AT+QAUDMOD and AT+QEEC is extremely limited. It may not be being set up correctly, or indeed at all, and probably needs sending on audio profile change which probably falls outside the usual things an audio profile change can do.