Q: 5s speaker suddenly stopped working.

Greetings mohtasham,

Thanks for using the Apple Support Communities!

I understand that you are not hearing sound from the speaker on your iPhone as you would expect. I see that you have already tried restarting your iPhone and the issue continues, too. 

To continue troubleshooting, I suggest reading over and working through the suggested steps from the following article to ensure that all relevant troubleshooting steps have been completed. 

If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support

Have a great day!