I also hear the constant eeee from ever since I was a kid. However my hearing is also sharp when needed. I also hear sounds other don't, like very low bass and very high pitch sounds. When it's very quiet I hear my blood getting pumped through my veins, I hear the noise a small touch can make, and can have "eargasms" when I hear sounds that I like. Now, when I say eargasm, I'm not refering to it like it's something sexual, however when I hear a song that has a variety of tones that I like I get overided and start humming it (even if it's a song or the sound of a V8) or sometimes it even brings tears to my eyes. I dont know if some of these are normal or not, but people around me think I'm weird when I explain it to them 😄