Q: loud squelching while talking on Iphone 6.

Hello ff4vt,

Thanks for using Apple Support Communities.

I see from your post that you're hearing an odd noise coming from either the speaker or receiver on your iPhone.  If you're hearing this while you're holding up the phone to your ear through the receiver, then please follow the link below.

If you can't hear a person on a call or voicemail or if the sound quality is poor on iPhone - Apple Support

If the sound is coming from the speaker on the bottom of your iPhone, then please follow this link:

If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support

Take care.