Most audio faults are not faults. A microphone that records nothing, an earbud that has gone quiet, noise cancelling that stopped cancelling — each of these has a short list of settings and connections that explain it far more often than broken hardware does.
So every page here runs the cheap checks first, in the order that rules out the most for the least effort, and only then describes what a genuine hardware failure looks like and how to tell it apart. Where a symptom differs between operating systems or between wired and wireless connections, the page splits the path rather than averaging them.
Wiring standards get named explicitly, because that is where a lot of this goes wrong: which contact carries the microphone signal, and which adapters preserve it. A guide that ends with "try a different cable" has not told you which cable, or why.
Meet needs three separate microphone permissions, and Chrome adds a fourth you may not control. Of the 67 headphone listings collected here, 30 have no microphone at all.
A laptop's microphone array is soldered into the lid, so the fault is a setting, a driver, or one of the 30 devices here that arrive carrying a microphone of their own.
The plug on the cable and the socket it goes into fail in different ways, and search calls both of them the same thing. Across 278 product cards, 64 state a wired connector, only 34 say how many contacts it has, and 26 of the 34 cables that exist come off — which is the whole diagnosis.
Only three Apple product lines have listening modes at all, and AirPods 4 ships both with and without. One earbud in an ear cancels nothing until an accessibility switch is turned on.
A mono source always silences the right side; a broken conductor picks whichever side was bent more. On true wireless the right earbud may be the one carrying the link.
MicTested