Why is my call speaker not working?

[AC Question]

Hello, I have a S3 LTE (I9305) and when I press the 'Speaker' button during my calls, it does not go into speaker and/or it just stays the same level of sound.

Any help?

 

[Rukbat]

Does the speaker work on anything else, like music? If not, it's probably a bad speaker or headphone jack. If it does, it could be a bad update, a bad phone app or almost anything else (but those two would be the first suspects).