Photo: A pair of earbud phones from anMP3 player. The metal gauze on the front is "acoustically transparent": it letssoundout without letting (too much) dirt and dust in. The backs of some earbuds are completely sealed to stop sound from escaping (so they're similar to closed-back headp...
If you're unable to pair a new device, consider two solutions: either make one of your existing devices 'forget' the accessory to free up a spot, or reset the accessory to clear all existing pairings. You can find specific reset instructions by searching for 'reset [device name].' 7. ...