Websites Covertly Accessing My Mac Microphone Through Safari

From what I read online about how the Mac Lock Screen should function under MacOS Tahoe 26 -  it should not be shutting down or turning on audio inputs unless the Mac is sleeping (this works differently on a MacBook because there is an automatic disablement of audio when the lid/screen is closed).  Even then, some audio connections, such as those that are currently streaming media, can continue to operate as an audio output. In other words, a software override is possible.  If this is true, something is fundamentally broken or there are undocumented Apple features causing Safari to open my mic for no good reason.  I was also unable to find any references to Safari scanning audio ports when the screen is unlocked.  Therefore, I believe that there is a current MacOS/Safari bug, or at least an undocumented feature that causes Safari to open microphone channels just after a Lock Screen state is unlocked.  Regardless, there appears to be no straightforward way to correct this Safari behavior of automatically enabling listening from an audio input when the screen is unlocked.  Since I received no feedback from the community to date, I am putting this problem to bed. I hope it will be address in subsequent Apple software releases.  

However, I did find a workaround which seems to function well.  Apple has several microphone mute apps in the Apple App Store for MacOS.  My favorite, of the ones I tried is Mic Drop, because it allows a number of different visual presentations for the mute button. Other similar apps seem to work just as well, such as Microphone Lock and Mic Control.  The software mic mute switch allowed me to both block all audio sources and to select the one audio input I want to remain active (which I can also mute at the push of a button).  I have it configured so my professional desktop mic is unlocked while all other audio input sources stay locked.  So, my current default state is all microphones are muted and when I click the mute button in my Menu Bar to On-Air, my desktop mic is the only live audio input.  I was pleased to see that all mic mute apps I tested kept Safari from opening my microphone input for no apparent reason. With this application running, no rogue audio listening apps can spy on you, which is becoming a bigger concern in the age of AI.

The microphone mute applications are simple enough to set-up, configure and use. It just takes developing the habit of remembering to enable the mic as needed and muting it when done.

BTW: Similar camera lock applications can also block any video spying and many will block your audio at the same time.  Though I didn’t test any of them enough to recommend one.  If you are in the habit of putting a piece of tape over your webcam you might prefer one of the video blocking apps instead.

To debug this, I unplugged each peripheral one at a time. I never realized I had so many devices with built in microphones.  I also removed software libraries/drivers for each app to try and discover if any of them have an audio input component.  Basically process of elimination. I was able to force trigger the microphone alert more easily now that I have a KVM switch installed, because switching peripherals between computers with the KVM Switch can happen at-will where each switch back to my Mac was subsequently triggering a microphone activation.  

Through trial and error I have found that many devices and software applications have built in microphones.  For instance I discovered microphones on the following devices: a Dell computer monitor, an external video camera, a headphone extension cord adapter, an iPhone that is being used as a wireless microphone, as a remote microphone even when it is not plugged in to my Mac or even in the same room, etc..

The bottom line is that I narrowed the culprits down to 2 items: The microphone in my desktop monitor and a software component called AudioCast, which I am still not sure what application it is associated with.  It seems to be an audio component that is used for separating out audio tracks and streaming audio.  When both of these elements are removed, Safari doesn’t activate a microphone. Both the monitor and audio processing component are more than 10 years old and have apparently been on 3 or more different generations of my Macintosh computers. AudioCast probably passing from one to another when restoring a backup onto a new Mac.

So here is the question.  Why did this problem only manifest over the last month when the elements causing the issue were around for many years?

I was able to determine that Yahoo was one of the websites that was causing my microphone to become activated. When I navigated to the site my microphone was immediately activated. I was able to see that my microphone setting was set to "Ask", but I was never asked for permission. I subsequently, changed the microphone setting for Yahoo, Yahoo Finance and Yahoo Sports to Deny. After which subsequent visits to those sites did not activate my microphone. However, it did not end my issue with my microphone being activated when my monitor screensaver is on, or perhaps just as my Mac's operating environment becomes re-activated (after the login display is unlock).

I am not seeing my microphone activating on websites in Safari for over a week (this is counting from when I discovered Yahoo was definitely causing my microphone to activate until I had set my microphone permissions to "Deny" for all of the Yahoo subdomains. (i.e. the setting of "Always Ask" doesn't work or doesn't work or perhaps not working the way I was expecting it to.)

However, I have still consistently seen my microphone activate when my Mac comes out of its screen saver.

I am regularly using several software applications that access my microphone, including Apple Sound Input under System Settings and a voice memo application. My microphone activates as it should when using those apps and deactivates after discontinuing the need for microphone usage (e.g. Activates microphone access only when in the sound control panel in system settings and immediately drops the mic when changing to a different control panel view in the MacOS system settings app.)

My issues with the Mic being activated by Safari is that it happens only when the system is idle and for no apparent purpose. Plus, the system microphone indicator for Safari stays on for roughly 20 minutes before disappearing, regardless of what web pages are open.

I now have my employer’s laptop (running Windows PC) and my M4 Mac mini Pro (running MacOS) sharing the same keyboard, monitor and mouse. They are connected with an external hardware KVM switch to transition between the two computers with the push of a button. 

Now, I am noticing my microphone being activated when switching my KVM back from my Windows laptop to my Mac mini. My Mac is still flagging Safari as the culprit. The mic activation happens every time I use the KVM to switch peripherals between one computer and the other. 

The only straightforward way to end the Safari microphone seizure is to restart Safari.  This makes no sense considering that web apps in the browser, such as those used for video conferencing, only activate the microphone when the requesting site is accessed in the browser. Safari discontinues use of the mic as soon as the respective browser session is closed (i.e. does not require quitting Safari).

This is what I am seeing/experiencing

1) Safari activates a microphone every time my Lock Screen is unlocked (i.e. Unlock Password is successfully used)  

2) There is no indication of which specific audio devices/inputs are being activated/connected, only that they are all associated with the Safari app.

3) The Microphone stays activated (Orange Mic Icon visible in Menu Bar) until 20 minutes elapses or Safari browser is restarted. 

4) This happens regardless of what Safari browser window is open or what audio input is selected in Sound Control Panel. 

5) The event can also be caused at-will by swapping computers using a KVM switch (Lock Screen activates every time the monitors are switched to the Mac mini). 

Can anyone validate if the observed behavior is normal/reasonable to see, under any circumstance, when the Lock Screen is being unlocked?

What I believe is happening (assumptions)

a) Safari scans for attached devices (virtual or physical audio inputs) when the Mac’s screen is unlocked. 

b) Safari locates one for more devices and activates the audio input channel(s). 

c) The activated device is a virtual input, because physical devices can all be unplugged and the event still triggers.

d) Residual audio software technology is still activated in the background. It is possibly looping inputs into a virtual audio channel that is open.

Can anyone validate if the assumptions above are possible, and if so, under what circumstances such behavior could manifest?