So back when I played on live servers, I've always noticed this ear ringing drone on the main menu. While the song was always amazing and still brings back memories, it hurts to people who have the proper audio peripherals or even ears to hear it.
There's a drone at about 15732.01Hz that is completely piercing through the mix of the song. Almost similar to that beep/drone coming from an old CRT TV. It's a very high frequency that some people actually get tinnitus from and start hearing when in absolute silence, since it was around us all the time with CRTs.
This seems to be officially called a "Flyback Whine" and is said to be "In television sets, this high frequency is about 15 kilohertz (15.625 kHz for PAL, 15.734 kHz for NTSC)" The whine coming from CoH seems to be this exact scenario. Weird since it's a recording and .ogg file and shouldn't include NTSC Flyback Whine, but maybe they had trouble when recording the track for City of Heroes.
I have attached an image of the peaking frequency and I've personally adjusted the .ogg file to cut out that frequency. I received the original .ogg from this website: https://archive.paragonwiki.com/wiki/Music
Attachements;
1) Image of Frequency
2) Original Song
3) Fixed Song
The file size is larger because I exported at a higher quality, even though the audio doesn't provide that quality, this is mainly to preserve all of the original.
H_music1_loop_new.ogg
H_music1_loop_new FIX.ogg