ho do i install a audio driver on my 2015 macbook air?

Hey Marco4242,

Thanks for posting your question in Apple Support Communities.

It is not usual for audio drivers to be removed on your Mac so you may first want to try scanning your Mac for any malware that may have removed them. You can try restarting your Mac, resetting your SMC, and resetting your NVRAM in order to restore your Mac's audio functions.

You can find steps on how to troubleshoot your Mac in the following articles:

• How to reset the SMC of your Mac.
• Reset NVRAM or PRAM on your Mac

You can download software in order to scan your Mac here: Malwarebytes

Best Wishes