Did you know that ear phones can be used as a microphone in a pinch? It can be plugged into the microphone socket of your computer or similar device for this purpose. The earbuds have a stereo jack so only plug it in half-way (one click) for it to record successfully, then hold the earbuds together to use as a regular microphone.
Many people don’t realize that there is a magnet inside of each earbud. If you drop a ferrimagnetic item in a crevice, down a drain, or similar hard-to-reach area you can remove the ear-side cover of the earbuds and expose the magnet within. You can pull back the plastic housing to allow full contact of the magnet’s surface and lower it down to retrieve what has been dropped. The magnets can be quite strong as illustrated in the photo where it actually held up a combination lock! For tiny crevices you can straighten out a paper clip and attach the earbud magnet to one end while using the other end to pick up the item. The magnetism is transferred throughout the length of the paper clip.
The magnet can also be used to magnetize a needle or paper clip by stroking the length of it in one direction several times. The item magnetized can then be used as a compass needle when floated on water or suspended in air by a thread.
Of course an obvious use of earbuds would be that of cordage. The uses of cordage are almost countless so you’re only limited by it’s strength and length. Some earbud cords use twin wire without an outer sheath so it can be pulled apart lengthwise to double it’s length for use. I often use my earbuds to compare the width/length of different items by placing the jack at one edge of an item then stretching it out to the opposite edge and pinching the cord as a marker then holding it next to the item or space for comparison
Earbuds can be purchased “on the cheap” at a thrift store so they would be affordable to acquire for testing any of these examples to build your experience base for future needs and emergencies.