why does only my speaker phone not work

[AC Question]

My phone works perfectly if calling normally bit a few months ago suddenly if i go choose speaker phone i can hear but no one can hear me.
If i go back to normal mode it works fine.
When using a video chat
program i get the same result

 

[the tall guy]

Hi, have you tried taking the phone to a repair shop to have someone look into it encase there is a problem with one of the phones mics?