There are certain sounds that have the ability to elicit either pleasant or non-pleasant memories. For me, a favourable auditory tone that conjures up a distant memory, both pleasing and painful, is the buzzing sound of a tattoo gun.
I have a 'patch' tattoo on my left shoulder and I'm working on another design for my right.
For some inexplicable reason (I'll have you know I'm no masochist) I find the sound of the machine, the constant buzzing and the different tones emanating from the gun when the artist moves it over my flesh, pleasing to the ear.
It may be my mood... but I long to hear that sound again. Soon. Maybe it's a sign.