This is a speaker that doesn't necessarily amplify sounds. I know, it sounds stupid. But it's better than a pair of frustrating headphones where only one side works. You only need one working side of a pair of headphones for this...thing. You also have to be okay with breaking these headphones. I wouldn't suggest doing this with expensive headphones however.
The point of this... thing is to be able to enjoy listening to audio with both your ears. It may be quieter than just using your phone or computer speaker, but you can enjoy the advantage of the long cord so you can set up a phone or computer like a TV and have the audio near you.
I know, I really have nothing else to do right now. But try this instead of throwing away those stupid headphones. I can't guarantee satisfaction, but I can hear everything clearly with these. This is not ideal for group use, but mostly for individuals who like sound quality. And have no judgement over my terrible DIY lol.
Step 1: Break the Headphones... With Care
So basically you want to break the headphones so you isolate the working side without breaking the cord.
Break off the good side from the band (look at the right "speaker")
Step 2: Break the Headphones Cont.
Don't separate the cord attaching the two ear muff things yet...
Step 3: Cut the Cord!
Cut the part of the cord attached to the ear muff thing you're NOT going to use, leaving the piece that attached the two cords to the single headphone jack cord. (The cord on the right is the one attached to the speaker/ear muff thing I'm going to use.)
Step 4: Lots of Length
This is just a picture depicting the length of the "speaker's" cord.
Step 5: Watch How This Does the Opposite of Amplify But Is Oddly Satisfying
I already know this DIY is a bust lol. YOLO. Uh oh, I just said "YOLO". (It's not as quiet as it sounds... listen to that quality)
(Btw the music playing is "High Hopes" by The Vamps, I don't own the music and I'm not promoting it... just using it as the independent variable for the testing of this thing.)