Hello MuznaMalik,
To help us get a better understanding of the issue, we’d like to ask a few questions.
1. Is there no sound at all, or only when using certain apps?
2. Were any changes made to your device settings before this happened? If so, what was changed?
3. Is Mute enabled on your device?
The above details will help us plan how to proceed.
Please check out this link, which explains how to check if Mute is enabled, and may help: If you can’t hear sound from your Mac speakers
If you can’t hear sound from your Mac speakers
First, make sure any volume controls in the app you’re using aren’t turned all the way down. Also, try playing a different audio file, CD, or DVD, or try playing the file or disc on another computer or media player to isolate the problem. Then, try the following solutions.
If you’re trying to listen through your computer’s built-in speakers
1. Unplug any headphones or external speakers.
2. On your Mac, choose Apple menu
> System Preferences, click Sound, then click Output. Make sure “Internal Speakers” is selected, the “Output volume” slider is not all the way to the left, and the Mute checkbox is not selected.

Thanks!