Why I am not able to hear sound from speakers

hello there,

actually there was a alot damage happened to my phone but after 4 5 months i repaired it from local store now everything is fine but suddenly while using my phone my speaker is not working but i am able to hear phone calls but no music is audible i tried 2 3 known ways to fix it but no response one more thing, speaker sometimes get okay but sometimes no audio please help