Sometimes, what appears to be a speaker issue is actually a microphone issue. How do you distinguish between the two? It is likely a speaker issue if you are experiencing poor sound quality or are completely deaf. It's probably a microphone issue if you can hear just fine on a call but nobody else can hear you.

Multiple speakers are available on your phone. On a phone call, you hear what is being said internally. Due to the pressure of the phone against your ear, it operates at a lower volume. When your phone calls or when you are playing music, you hear it through the external speaker. This sound is intended to be louder so that you can hear it from across the room, in your pocket, bag, or purse.

If your speaker isn't producing any sound, there is probably a hardware issue with the speaker itself. There may be other causes, though, if the sound is only distorted or alternately present and absent. There may be a connection issue between your phone and your carrier. It can possibly be a software issue brought on by a recent app download. If there is no connectivity issue after checking with your carrier, you might want to restart your phone. As a reset will wipe any data you have saved, be careful to perform a backup of your data first.