Roger Pen

Hi I have a new Nathos Auto UP on the NHS and today had an assessor come round who advised I would benefit from a Roger Pen and also the bit that attaches to hearing aid. I have searched but could not find an answer. I wanted to know if when you have a bluetooth device connected to the Roger Pen and transmit to the HA are you able to mute the mic of the HA for as long as you want so that all you hear is what is being sent over by the pen? I ask because in the past I tried to use the loop setting on my previous hearing aid together with a round the neck loop device that was connected over bluetooth to my phone and bike gps and while it worked as soon as I would start the bike there was much interference picked up. I would also get interference when trying to use the loop setting on an airplane too. 

It would be awesome if you are able to mute the HA mic and control the audio level of the device being used as I am certain there will be no interference like there was using the loop system.