Thank you for using the Apple Support Communities.
I understand that you are having issues with being heard while on calls. I found the following information that may help:
When someone calls, I can't hear them through the receiver or speaker phone, and I can't hear music through the speaker. I also can't be heard by someone who is calling me.
For other troubleshooting tips, see:
- iPhone: Sound muffled or low from the speaker or when speaking into the mic
- iPhone: Hardware troubleshooting