Noise cancelling headset
Noise cancelling technology was definitely a game changer. Almost every headset has them now, but I remember when they first started out. They didn’t quite work on helicopters, especially with two bladed systems and flying with the doors off. At least mine didn’t, haha. It was overcompensating for the rotor-slap and it felt like somebody was standing behind me slapping me on both ears simultaneously in the rhythm of the rotor-slap just slightly out of sync. I had spent all that money, never used them, and didn’t trust them for years.
I re-invested in this technology for the second time about 5 years ago, and now I cannot live without them anymore. They truly are the best thing ever. Protect your ears, young pilots! It’s something I wish I had paid more attention to over the years. It is now catching up with me.