Audio goes low pitch (M1 MacBook Air)

Hi m1_user_dbg,

Let's try to resolve the issue by changing the output settings using the steps here: Change the sound output settings on Mac - Apple Support that are also listed below.

1. "On your Mac, choose Apple menu  > System Settings, then click Sound  in the sidebar. (You may need to scroll down.)
2. Click Output on the right, then select the device you want to use in the list of sound output devices. 
3. All sound output devices available to your Mac are listed, including the computer’s internal speakers, devices plugged into your computer’s sound port (), USB speakers, and AirPlay devices.
4. For any device plugged into the computer’s sound port, choose Headphones.
5. Do any of the following to adjust your sound output settings:

• Adjust the volume: Drag the Output volume slider.
• If you have Sound in the menu bar, you can turn the volume up or down from anywhere.
  • To set a volume for alert sounds, drag the Alert volume slider in Sound Effects. The alert volume is relative to your computer’s volume, so if you lower the computer’s volume, alert sounds also play more quietly.
  • Stop sound output: Select the Mute checkbox.
  • Adjust the balance: Drag the Balance slider."

If the issue still occurs, then let's see if the issue exists in safe mode. You can learn how to boot into safe mode by completing the steps listed here: How to use safe mode on your Mac - Apple Support that are also listed below.

"Apple silicon

1. Shut down your Mac.
2. Turn on your Mac and continue to press and hold the power button until you see the startup options window.
3. Select your startup disk, then press and hold the Shift key while clicking “Continue in Safe Mode.”
4. Log in to your Mac. You might be asked to log in again.

Intel processor

1. Turn on or restart your Mac, then immediately press and hold the Shift key as your Mac starts up.
2. Release the key when you see the login window, then log in to your Mac. 
3. You might be asked to log in again. On either the first or second login window, you should see ”Safe Boot” in the upper-right corner of the window."

Best regards.