I’ve complained for years no matter the stethoscope that I couldn’t hear. I d had MDF & Littman. I’m sure a-lot of that was my fault as I do wear headphones for listening to music. But normally I was never clear on what I heard when listening to a patient. I no longer have that problem with this stethoscope. I can hear clearly the heart and lungs songs and I love that u can turn the volume up and down as well. I haven’t encountered someone with Afib while I’ve used my stethoscope, but I’m excited about that feature. It’s a great quality stethoscope and u get what u pay for. Beautiful design, beautiful colors you can mix and match and it’s very accurate. I used it to do my assessment on my patient and while the heart rate and rhythm showed up on the stethoscope, I looked up on the monitor to see if it showed the same thing and it did. This is a must buy and well worth the money.