When you use your hearing aids during a phone call, they will act as a microphone to pick up your voice. You can change this and use your phone microphone instead. Open the Fortell app, go to Account > Preferences and turn off Hands-free Calling.

Fortell app — Account > Preferences > Hands-free Calling toggle (1 of 3)Fortell app — Account > Preferences > Hands-free Calling toggle (2 of 3)Fortell app — Account > Preferences > Hands-free Calling toggle (3 of 3)