Can’t hear sound in my apple computer

Try this Link to Apple Support on this topic

Something like this happened to me a little while ago, and nothing except Siri made a sound. It was after my cat had been lying on my keyboard, and I suspect she turned on Siri by holding down cmd-space for a while. Just tap the Siri button and see if you get sound then. If you do, you might have stumbled on the same bug as I did; not sure having a cat is required!

When this happened to me a few months ago, simply trying Siri fixed it. This time it didn't but I it did get fixed when I did something like this:

1. Mute your mac.
2. Start Siri; normally, this would make a ding-ding sound but you won't hear that.
3. Clear Siri again.
4. Unmute the mac.
5. Start Siri again; it should make a sound now.
6. Try Zoom or whatever again; hopefully that works now.

Since I never use cmd-space to access Siri, I went into System Preferences > Siri and turned it off so my cat doesn't use it by accident; I'm hoping this doesn't happen again because it is a pain.

If above doesn't work, restarting your Mac might fix it.