Should I get a new stethoscope??

So I currently use a "UA Clear Sound Pink Ribbon Stethoscope" that I've had for like a year and a half. You can't beat the comfort of the earpieces and the sound is great. The only problem is: through the wear-and-tear of student work on the floors, I've noticed a few cracks in the chest piece, but not a huge difference in sound-quality (if there even is a change). My question is for you seasoned nurses out in cyberspace!! How often do you usually replace your stethoscopes? Do they have a shelf-life? Should I get a new steth before beginning my job in July? Thanks in advance for any responses !!