LockDown Browser Microphone Not Working on Mac (Permission Fix Guide)

Last updated 2026-05-01 · LDBypass Editorial

Symptoms

• "Microphone not detected" during Respondus Monitor system check.
• System check completes but recording shows silence on instructor review.
• Audio level meter stays at zero despite speaking.
• System Settings → Privacy → Microphone shows LDB allowed but it still fails.

Causes ranked by frequency

1. TCC Microphone permission stale (~38%).
2. Wrong input device selected (~28%) - system default is something other than the working mic.
3. AirPods / Bluetooth profile switching delay (~18%) - Bluetooth headset cycling between A2DP and HFP times out the system check.
4. Input volume at 0 (~8%) - input level slider all the way down.
5. Hardware mute / privacy switch (~5%) - some external mics have a physical mute.
6. Other (3%): kernel extension conflicts, beta macOS issues.

Fix 1 - Reset Microphone permission for LDB

1. System Settings → Privacy & Security → Microphone.
2. Toggle "LockDown Browser" off, then click the (-) minus to remove.
3. Quit LDB.
4. Relaunch from LMS. Click Allow on the prompt.

Fix 2 - Select correct input device

System Settings → Sound → Input. Select MacBook Air/Pro Microphone (built-in). If you previously used external (USB headset, AirPods), the system might still default to it. Switch to built-in for the system check.

Fix 3 - Avoid Bluetooth headsets for system check

If you use AirPods or other Bluetooth headphones, the Bluetooth profile switch from A2DP (music) to HFP (mic-active) introduces a 5-15s delay during LDB's system check. Workaround: select built-in mic, run the system check, then switch to AirPods after the exam interface loads.

Fix 4 - Verify input level

System Settings → Sound → Input. Speak and watch the input level meter. If it stays at 0, raise the input volume slider. Some macOS updates reset this to 0 silently.

Fix 5 - Test microphone in QuickTime

QuickTime Player → File → New Audio Recording → click the down arrow next to the record button → select your input. Test recording. If QuickTime captures audio, hardware is fine and LDB-side fix applies. If QuickTime also fails, the mic itself is broken.

Fix 6 - Reset TCC Microphone at system level

tccutil reset Microphone com.respondus.lockdownbrowser

Fix 7 - Disable Voice Isolation / Wide Spectrum

macOS Sonoma+ has a per-app Voice Isolation toggle (Control Center → Mic Mode while LDB is running). For some Logitech / Yeti USB mics, Voice Isolation produces silent recordings. Switch to Standard mode.

Fix 8 - Disconnect external microphone, use built-in

External USB mics occasionally trigger LDB's blacklist heuristics if they have on-board audio processing (some Yeti and Blue products). Built-in mic is always the safest choice for the proctored exam.