The sound on my MacBook Pro has become very muffled
The sound on my macbook pro has become very muffled.
[Re-Titled by Moderator]
Question marked as
Restart your Mac.
Try resetting NVRAM/PRAM http://support.apple.com/kb/ht1379
To trouble shoot further you can:
Try a SafeBoot https://support.apple.com/en-us/HT201262
Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc. Login and test.
This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.
Test issue in another user (or guest user) account https://support.apple.com/en-us/HT204443
This will tell you if it a universal issue or isolated to your user/admin account.