Detecting when head phones are plugged in

Question

Is there any way to determine, programmatically when headphones are plugged into the computer?

Essentially, I just want to write a simple tool that will mute my sound unless headphones are plugged in. Is this even possible?

Answer 1

It might be possible - RealTek has a system tray utility that pops up an annoying a helpful utility for tuning your audio whenever you connect something to the microphone jack, maybe the headphone jack is similar.

Answer 2

Not unless your soundcard provides support for it, which is doubtful.

It's conceivable that some soundcards have a microswitch in them to detect when a headphone is plugged in, or that they might measure the impedence of the signal to know when the circuit is closed. I haven't seen that in any cheap soundcards.

Now, if you have a jack that is shared with a microphone ( e.g., a headset ), you might be able to detect the "pop" on the microphone channel, but I would hazard that would still be pretty unreliable. You wouldn't know if it was being plugged in or removed, just that a change had occurred.

Personally, I just mute the sound all the time, and only turn it on when I really want sound.

Answer 3

I think you cannot provide a universal solution.

I also point out the nray's solution. Most Realtek sound cards, Specially realtek on Intel main boards has this feature. But in that case the hardware is not a "Standard" one. In other words in those sound cards there should be special mechanism to detect the change in resistence over the nodes of the output sockets and "Fire an event"

If you have that sort of sound card + you just need a working, but not perfect solution, Just modify the routine that calls the configure program. (A program to mute/unmute ). Then replace the configurer program (You may find it using process explorer) with your new utility.

N.B I am not 100% sure whether we can identify plug in - plug off distinctly.

Answer 4

Many audio codecs provide "jack detection", that's probably the term you need to google.

It appears that under Vista, you can use IMMDeviceEnumerator::GetDefaultAudioEndpoint() and IMMDevice::GetState() to check the state of an 'endpoint'. There is also the 'IKsJackDescription Interface'.

Under XP you might try 'waveInGetNumDevs' - the driver may report 0 until the headphones are plugged in. See the comments in this discussion for more info.

Answer 5

In Windows Vista and beyond, you can use the device arrival and removal notifications and retrieve the endpoint formfactor to determine if the manufacturer of your audio solution considers a particular endpoint a "headphone".

Before Vista there was no way of determining this information.