According to various embodiment of a method of operating a hearing instrument, an acoustic signal pathway is provided from a microphone through a signal processor to a hearing instrument (HI) receiver in an acoustic mode of operation. An RF transmit signal pathway is provided from the microphone to an RF transmitter, and an RF receive signal pathway is provided from the RF receiver through the signal processor to the HI receiver in an RF mode of operation. An input signal representative of sound detected by the microphone is adaptively filtered. A first adaptation rate is used for the acoustic mode of operation and a second adaptation rate is used for the RF mode of operation. The second adaptation rate is faster than the first adaptation rate.