I program for a living and I work in small 8x8 office with 2 computers. within 8 foot of my office there are 10 more machines. 9 hrs a day 5 days a week I sit in this room and listen to growling of the cheap-ass fans they use on these systems and it starts to get to you... its even worse that I am sensitive to high pitched sounds.
Before they remodeled and I was in a nice big space over on the other side of the building, all by my lonesome... everything was groovy...
Its just noise saturation. Some people have a higher threshold, and some just work\live in environments where the noise or stress levels overwhelm you and you just want some silence...
Funny thing is, my main source of transportation is a motorcycle, and I love to escape the whirring fan noises by going for a ride... you know, on the noisy bike on the noisy streets... ahh how relaxing.