Can't hear recording from a cassette but can see sound waves

Hi there, can someone please help?
I’ve recorded a piece from a cassette and it all looks fine as I can see the blue sound waves, but I can’t hear anything on playback. Yes, the volume is up. Yes, I have checked Software Playthrough.
Thank you.

Audacity has to be pointed to a real playback device and it has to be relatively simple. The headphone output of your laptop may be a simple device and work perfectly, but a headset connection (headphones and microphone built-in) may not.

What is your playback system? My Mac laptop built-in speakers work perfectly if Audacity is pointed to them.

Do you have competition for the sound services? Skype, Chat, Games or Conferencing? All of those may reassign speakers and microphones to suit their purposes—and not always tell you.

You can have Magic problems, too. Is it a stereo show—two blue waves? If you magnify them (sideways), do most or all of the waves go in the same up and down direction? If they don’t, you may have a phase damage and the song will not play on a mono speaker system.

Koz

Hi Koz, thanks for your quick reply. The headphone/headset output that I’ve put the jack into is the only one on my desktop Mac.

Sorry, I don’t know what you mean by ‘what’s the playback system’? I’m using OS 10.13.6 if that helps. I don’t game, nor use the other apps you mentioned. I’ve attached a screenshot of what part of the recording looks like.

Thank you.
Screen Shot 2019-01-06 at 11.32.15 PM.png

I am beyond embarrassed.
Here’s me trying to playback recorded files with the offing jack still in the computer.
I’ll go die in the corner somewhere akay…