Oftentimes, people end up buying a new set of earbuds simply because they look nice or they are priced affordably. However, that isn't always going to provide you with the quality you need. You need something affordable and reliable, not just something that looks cool. Buying earbuds is all about knowing what you are getting in relation to what you need and want. To help you better understand what earbuds to buy, here are a few numbers you need to understand on the packaging.
Just about every package you pick up with earbuds in it is going to have a frequency rating. Frequency is measured in hertz. Lower hertz means more bass. Higher hertz means more treble. If you see something that says kilohertz, that often doesn't matter. Focus simply on the hertz. Human ears are only able to hear up to a certain point anyway, so you don't want to overdo it with the kilohertz. Look for something around the 30-40hz range to get a good mixture.
Earbuds are powered by electricity. You might not realize it, but electricity has its own vibrational frequency. Those vibrations cause a hissing noise. To help eliminate as much hiss as possible, you want a higher impedance number. More OHMs mean you are going to get a clearer sound. While higher OHMs also mean higher price, you want to go with whatever pair fit in your budget.
You want to know how much power your earbuds are capable of handling before they end up wearing out on you. Maximum power supply is listed on the package, so make sure to pay attention to this number. Using your earbuds at the lowest level possible will help maximize their life. You don't need to have them blaring out just to hear the music.
Sensitivity levels are calculated in decibels. You don't need a pair of earbuds that can produce 200 decibels of sound--that is, unless you want to go deaf. Your ears can only take so much before you rupture your eardrums. Regardless of how loud you think you need your buds to be, you don't need them any higher than say 75-80 decibels. This will protect your ears and still give you a decent amount of volume.
Don't just jump into a new pair of school earbuds without first doing your homework to know what it is that you are buying.