You need to replace the KEXT file AppleUSBAudio.kext with an older version. You do all this via “su” or logged in as root.

Here’s how to do it (re-written from here):

1. Download the AppleUSBAudio.kext from 10.5.6 here.
2. Unzip it.
3. Open up terminal
4. Make a backup of the existing driver by running the following in terminal
   
   cp -Rp /System/Library/Extensions/AppleUSBAudio.kext ~/Documents/AppleUSBAudio.kext-BACKUP

5. Exit any applications that are using a USB audio device and unplug all USB audio devices. In my opinion, print this page and restart your computer and ONLY open terminal. Unplug your headset please.
6. Unload the existing AppleUSBAudio driver from the kernel by running the below command in terminal.
   
   sudo kextunload /System/Library/Extensions/AppleUSBAudio.kext
   
   If you get an error saying ” not found for unload request” your fine. If you get an error claiming it can’t be unloaded because its in use (don’t have the text in front of me) then stop and go back to step 5.
7. Remove the existing driver by running the following in terminal.
   
   sudo rm -rf /System/Library/Extensions/AppleUSBAudio.kext

8. Put the new driver in place by running the following in terminal.
   
   sudo mv ~/Downloads/AppleUSBAudio.kext /System/Library/Extensions/AppleUSBAudio.kext

9. Remove quarantine (OSX Snow Leopard and Leopard):
   
   xattr -d com.apple.quarantine AppleUSBAudio.kext
   
   You can see if it was quarantined by running this:
   
   xattr -l AppleUSBAudio.kext

10. Load the new driver by running the following in terminal.
    
    sudo kextload /System/Library/Extensions/AppleUSBAudio.kext
    
    Note: At this point if you get an error like this:
    
    check the system/kernel logs for errors or try kextutil(8)
    
    Do the following:
    
    chown root:wheel /System/Library/Extensions/AppleUSBAudio.kext
    chown root:wheel /System/Library/Extensions/AppleUSBAudio.kext/*
    chown root:wheel /System/Library/Extensions/AppleUSBAudio.kext/*/*
    chown root:wheel /System/Library/Extensions/AppleUSBAudio.kext/*/*/*
    chown root:wheel /System/Library/Extensions/AppleUSBAudio.kext/*/*/*/*

11. Confirm the new driver is loaded by running the following in terminal.
    
    kextstat | grep AppleUSBAudio
    
    The output should look like the folliowing (the 2.5.8b13 is the important bit, some of the other numbers might be slightly different):

    sh-3.2# kextstat | grep AppleUSBAudio
    129    0 0x92cdc000 0×28000    0×27000    com.apple.driver.AppleUSBAudio (2.5.8b13) <99 98 36 14 8 7 5 4 3 1>