GamingFind the first failing layer
Open System Settings, Sound, Input. If the device is absent, investigate connection, power, and discovery. If listed, select it and watch the input level while speaking. If the meter responds, macOS sees audio and the remaining fault is likely app selection or permission.
Note the exact device name. For an analog XLR microphone, the Mac lists the connected interface or mixer.
Check connection and interface state
Connect USB directly during diagnosis, reseat the cable, and remove unnecessary hubs or adapters. For an interface, confirm power, channel, hardware mute, gain, and any microphone-specific phantom-power requirement.
If the device has vendor software or firmware, use the manufacturer's current compatibility instructions. A known-good cable and a second host can isolate a hardware fault.
Select and set the Mac input
In Sound, Input, select the intended device. Apple provides an input level meter and, for applicable devices, an Input volume control. Speak from the normal position and confirm consistent movement.
If the meter is flat, return to the hardware path. If it moves but is tiny, adjust hardware gain or input volume without driving loud speech into distortion.
Grant per-app access
Open System Settings, Privacy & Security, Microphone and enable the app. An app that has not requested access may not appear until it tries to use the microphone. Quit and reopen it after changing permission.
For browser apps, check the browser and site's own permission as well. A successful system meter does not override a denied app permission.
Compare another recording app
Make a short recording outside the failing chat app. If that recording works, do not keep disturbing the cable and gain; focus on the application's chosen input and access.
If every app fails while the Sound meter moves, recheck privacy and any routing utility. If the device vanishes under load, investigate the connection, hub, power, or vendor support.
Keep the Discord exception narrow
Discord documents an issue for its macOS voice service with some USB audio interfaces that accept XLR microphone input. It applies to that Discord-on-macOS interface path, not to every Mac app, interface, USB microphone, or XLR microphone.
The relevant pattern is: the interface appears in macOS and records in another app, but Discord cannot use that XLR-interface input. Follow Discord's specific workaround or choose another supported path.
macOS can change the selected input when a display, dock, phone microphone, headset, or interface connects. After the system test succeeds, select the same named device inside the target app. If the app follows System Default, confirm the Mac input again after every connection change during diagnosis.
Save a ten-second reference recording once the path works. Include normal and louder speech and note the hardware gain position. If the problem returns, comparing the new system meter and recording with that reference will show whether the change happened before the Mac, inside app permission, or only in the chat service.
If an interface exposes several channels, the app may expect a particular mono input while another recording app accepts a stereo pair. Confirm the vendor's channel layout and the app's input options. A meter moving on interface input two does not guarantee a chat app reading input one receives it.