Audio recording, sound stopped

Going through recordings listening for various sounds, discovered three searching for, go back to listen to them again, to write down details when these occurred and all of a sudden no sound heard.
Running macOS 13.7.2
Audacity 3.4.2.0
Attempting switching off/on, unplugging/re-attaching, switching off/on iMac, unloading/reloading = no sounds heard.
Attempted to click on Audio Settings, nothing opens.
Only thing that might have occurred is I’ve accidentally touched something on keyboard, but what to lose audio sound I don’t know.
The screen appears to show everything as normal, the JiGMO recording device plays audio, but playing through usual Audacity on iMac no sound now being heard.
Any mystery solvers help appreciated.

The sound you want to listen to - where does it come from? Are you playing the sound using Audacity, or using any other application? Is it a sound file on your computer? Is it something playing via the internet (for example, a youtube video)? It would help a lot if you tell us what you (are trying to) do.

What is JiGMO? What else is connected to your computer, and how?

Thanks for the reply mac-christian.
For a number of years I’ve used a JiGMO recording device, to report various incidents relating to internal noise from my neighbours (on Police advice). JiGMO is a small 32GB recording device, which is connected by USB cable to iMac.
Upload these recorded files to iMac, then use Audacity to load and play back recordings. Files are in .WAV (Waveform audio) format.
I scroll along to the incidents highlighted by increase in sound level to find out what these relate to.

When undertaking the playback of these recordings, on Audacity, they were working fine, then all of a sudden could not hear any sound, although Audacity screen was showing the file was being played.
Have played back some of these .WAV recordings successfully through ‘Music’ App on Mac, which can be heard, as well using ‘Play’ through JiGMO recorder, so the issue seems to be with Audacity connecting to Mac somewhere, unless another known issue is occurring.
Hope this provides information to assist.

So the WAV-files are on your Mac when you try to play them, right? Are they on your internal drive (well, an SSD is no longer a “drive”, since there are no moving parts inside, but still…)? What I have read in this forum is that Audacity does not like external storage devices at all. No matter whether they are external disk drives / SSDs or cloud storage.

When they are playing as expected in Music.app, you could try to convert them to another format Audacity understands (AIFF, for example). However you should not try a lossy format like .mp3 if you want to do something with the file in Audacity. You know how to convert a file using Music.app?

I myself have never used Audacity 3.4.2, so it could be a bug in this version (although I do not really believe that). If you do not have too many individual settings for Audacity, you could try first to remove the folder
~/Library/Application Support/audacity
(not delete it, just move it somewhere else, for example to your desktop) and see if the problem is gone. If not, try another version of Audacity.

So the WAV-files are on your Mac when you try to play them, right?
Well they were being read from JiGMO, so copied one WAV file to desktop.
Attempted to convert this file to AIFF format, mac instructions were to use Music>Settings>Files>Import Settings but the option to convert from was not highlighted. Managed to press ‘Option’ key which allowed conversion, it bleeped to say completed but still having same issue - no sound!
Notice the file still has .WAV extension.
Police have just attended, could not resolve issue so they request I inform them when find the solution! Struggling to find ~/Library/Application Support/audacity
Have just update Audacity to latest version, still no sound heard.
Could these files have become corrupted?

Using Audacity help section managed to find ‘Resetting Audacity’ which undertaken, without any change.
‘Purging the Settings Folder’ undertaken, without any change.
Looked through Audacity headings, finally success!
Under ‘Extra’ ‘Mixer’ adjusted to maximum ‘100’ sound has returned.