If Windows notifications or another application are audible, a single silent app may have its own mute, volume or output setting. Raising the main volume repeatedly can make other sounds unexpectedly loud while leaving the failing app unchanged.

Choose a short sound or recording whose contents you know. Start with a moderate speaker or headset volume. Confirm that the affected app is actually playing, rather than paused or waiting for a download. Keep the output device connected throughout the comparison.

Inspect the app's mixer entry

Go to Settings, System, Sound, Volume mixer. Under Apps, find the relevant application while it is active. Check its mute state and volume slider. Then inspect its selected output device: Windows allows an app to use an output different from the system default.

An old selection can be confusing after moving between a headset, monitor speakers and laptop speakers. Choose the output you intend to hear. If the application has an internal speaker or audio-device menu, inspect that as well; a meeting app's call output deserves particular attention.

Change one setting and replay the same sample. If the app needs reopening to adopt a device change, save its work first. Do not begin by removing every audio driver when the evidence points to a single application path.

Test the return to normal use

Once the sample plays, try the actual activity that failed, such as a call preview or training video. If you normally disconnect the headset afterwards, check how the app behaves when it is connected again. Document an app that keeps returning to an unavailable output.

If the same device is silent in every application, broaden the investigation to its connection and system-level configuration. If only one file is silent, compare another file in that app. These distinctions help avoid replacing working speakers to solve a setting or content problem.

Reference: Microsoft Support.