How to detect microphone usage on OS X?

Question

Is there a way to detect when the microphone of my Mac is in use? Similar to what Mikro Snitch does? Can this be done in Cocoa?

score 7 · Answer 1 · answered May 18 '17 at 20:50

7

This isn't really an Objective-C or Cocoa solution, but if you're willing to do a subprocess call, try this:

ioreg -c AppleHDAEngineInput | grep IOAudioEngineState

You will see "IOAudioEngineState" = 1 when audio input is active.

Also, try searching for IOAudioEngineNumActiveUserClients which increases by one for each app taking in audio.

answered May 18 '17 at 20:50

kgutwin

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2

I just discovered this may only apply for the internal/built-in microphone... the IOAudioEngineState remains zero when using a bluetooth audio device. – kgutwin Jan 24 '18 at 16:23
1

I know this is old question, what about latest 2019-2020 mic? – pregmatch Jun 06 '20 at 13:09

score 5 · Answer 2 · answered Sep 20 '16 at 12:58

Is there a way to detect when the microphone of my Mac is in use?

Simple answer - Yes, but it's not going to be easy!

Can this be done in Cocoa?

As the documentation states: -

The Cocoa application layer is primarily responsible for the appearance of apps and their responsiveness to user actions

So this doesn't cover the microphone and if it did, it would be too high level for what you want.

A detailed answer on how to do this is complex and too broad for Stack Overflow. However, to set you off in the right direction, you need to create an IOKit kernel extension driver (KEXT) and have a good understanding of the I/O Registry

score 4 · Answer 3 · answered Oct 23 '20 at 19:37

4

My previous answer no longer works and was rather brittle (it only applied to the internal device). This is a quick solution for PyObjC, which can be translated to Objective-C or Swift reasonably easily.

import AVFoundation
import CoreAudio
import struct

mic_ids = {
    mic.connectionID(): mic
    for mic in AVFoundation.AVCaptureDevice.devicesWithMediaType_(
        AVFoundation.AVMediaTypeAudio
    )
}

opa = CoreAudio.AudioObjectPropertyAddress(
    CoreAudio.kAudioDevicePropertyDeviceIsRunningSomewhere,
    CoreAudio.kAudioObjectPropertyScopeGlobal,
    CoreAudio.kAudioObjectPropertyElementMaster
)

for mic_id in mic_ids:
    response = CoreAudio.AudioObjectGetPropertyData(mic_id, opa, 0, [], 4, None)
    print('Mic', mic_ids[mic_id], 'active:', bool(struct.unpack('I', response[2])[0]))

Note that this script will work once through, but if your app does not have a run loop, as observed in this question, repeated calls to AudioObjectGetPropertyData will always return the same result.

answered Oct 23 '20 at 19:37

kgutwin

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1
10
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Just started a new Swift project and seem to get a lot of deprecated features when tryin get at the mic from `AVCaptureDevice`. I think `devicesWithMeidaType` was replaced with `devices` which is now deprecated in favor of `AVCaptureDevice.DiscoverySession`. Seen this answered two days ago and was curious if you were targeting old frameworks? Trying to just write some fun code to know when the mic is on but seems strangely difficult on macOS. – afreeland Oct 26 '20 at 02:00
1

@afreeland I was using old code samples - it works for me on Catalina, and while I saw that deprecation warning, I ignored it because I just wanted to get it working... if you get it working with `AVCaptureDevice.DiscoverySession`, can you post your code? – kgutwin Oct 26 '20 at 12:33
Is there a way to determine which application is using the microphone, like the menu bar widget in macOS? – iloveitaly Jul 10 '23 at 23:40

score 2 · Answer 4 · answered Jan 13 '21 at 07:52

I'm working on go module that detects camera/microphone state (using cgo) and here is my crafted Objective-C implementation for IsMicrophoneOn(): https://github.com/antonfisher/go-media-devices-state/blob/main/pkg/microphone/microphone_darwin.mm

I used kAudioHardwarePropertyDevices to get all audio devices (microphones + speakers) and then [AVCaptureDevice deviceWithUniqueID:uid] to filter out only microphones by device UID.

score 2 · Answer 5 · answered Feb 05 '21 at 21:08

2

Based on the solution of @kgutwin I was able to find a way to get the active state of the mic on MacOS Big Sur. Actually only exchanged the -c with an -l. So all kudos to @kgutwin.

ioreg -l |grep IOAudioEngineState

answered Feb 05 '21 at 21:08

jbasement

21
2

This was helpful thanks. If you run this it will just output the boolean value: `ioreg -l | grep -o "\"IOAudioEngineState\" = 1" | wc -l` – Caleb Lawrence Mar 26 '21 at 23:32
2

This works on Mojave using the built-in mic, but not using Bluetooth headphones unfortunately. – ultrafez Jul 26 '21 at 18:00

How to detect microphone usage on OS X?

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