bluetooth sound muffled in phone calls hard to hear other person they cant hear me

[Android Central Question]

i have a pioneer fh-x720bt installed in my car and i was using the Bluetooth fine on for for the last 3 weeks since i installed it however for some reason when i can people now or receive calls they cannot hear me and i can barely hear them with them sounding very muffled through the speakers. what happened to the radio and can i fix it?

 

[B. Diddy]

Welcome to Android Central! Does this only happen with that head unit? How about with a Bluetooth headset?