microphone issue

Siri hears me when I dictate so it isn't that, I just have issue when making phone calls. Have to put on speakerphone when making a phone call. This happens with both phones and since 8.3.

Try an SMC reset Resetting the System Management Controller (SMC) on your Mac - Apple Support

If that doesn't work, go to Apple Menu> about this mac> more info> system information> hardware> audio

See if it lists a built-in microphone, if not, get it serviced.