How can I further reduce the background noise when using Roger On microphone?

Some hearing aids have the ability to change the balance between hearing aid microphone and streaming signal via the hearing aid app. Change the balance more towards the streaming signal to reduce the noise that is picked up by the hearing aid.

Another option is to ask your Hearing Care Professional to configure a hearing aid program that attenuates or disables the hearing aid microphone. Once such a program is available in your hearing aid, change to this program.