The reaction to chimes IS in the mind.
Other people can hear them as well. But, for some reason, they don't get irritated.
And the more a person worries about a problem like this, the worse the problem becomes. It can gnaw away at them.
Yes, some people are more sensitive to aural stimulation than others, just as others are more sensitive to other sensory stimulants, but this is because of the way their brains are wired. I work with people with autism, and to put it very simply some of them have high levels of sensitivity to various stimuli such as sound, touch or taste, and others whose sensory receptors are dulled and they can tolerate much firmer touch, louder sound, coarser textures etc . Although we still have a lot to learn about the nature of autism, what we do know is that we all have these tendencies to some degree.
To say that 'it's all in the mind' is not true ; however it is 'in the brain' and if that is the way your brain is 'wired' and you are susceptible to certain sounds then there is nothing you can do to change this and if people have to put up with stimuli that are, in effect painful, is like torture.