[kkielhofner]

Is this done physically/electrically?

Echo devices, for example, were sold as having a "hardware mute switch" from day one. Sure enough, teardown after teardown[0] has confirmed the hardware mute switch actually physically disables the mic (cuts power to the ADC, mic lines, etc).

If this is implemented in software it's no different than a phone and worse than an Echo.

[0] - https://electronupdate.blogspot.com/2021/01/amazon-echo-flex...