Chosen Solution

The speaker does not work on my phone. The Bluetooth and headphones works fine and the vibration is fine as well!!

The top speaker in your phone? if so it does not work and needs replacing

Try the volume buttons, if no volume bars appear, then the charging port is faulty. First clean the iPhone charging port with a toothbrush and isopropyl alcohol very well. If still problem the next step would be replacement of the charging port assembly with flex cable, lower mic and home button flex connector all a single part.

Headphones provided with a mic are called a headset. Alternatively, headphones are created to produce sound only. Resource : http://www.headphonesencyclopedia.com/be