@Haejin,

Bro, I am having trouble hearing your videos. It seems your microphone volume is turned too low, or you need to enable the dB booster in sound settings.

I literally have my sound at 100%, video at 100% and I still cannot hear you. I can barely tell you are speaking.

I've had this problem on a few other videos, but definitely not this bad.

I'm sure all of us would be glad to chip in for a new mic for you :)