Q: internal iphone6 speakers not working

Hello raconfused, 

Sorry to hear that you are unable to hear people when making phone calls on your iPhone. That is some that can be resolved with some troubleshooting 

Start with the article below. It will have you check if the you are attached to any bluets devices as well as cleaning the receiver. If after trying everything in the article and you still do not have sound from the receiver, you will then need to contact Apple Support for further assistance. 

If you can't hear a person on a call or voicemail or if the sound quality is poor on iPhone
https://support.apple.com/en-us/HT203800

Take it easy