> because hyperacuity has nothing to do with activity it is a pathalogical reaction to noise
just had a google as I'd not heard of it and like to find out about things - google isn't much help but have found that 'hyperacuity' is an acute sense, so for your dog it's auitory hyperacuity - an acute sense of hearing?
Your poor dog, do you know the cause? Is it something they're born with
(ie, there is no underlying reason - that's just the way it is)
or is it caused from something else - an underlying condition?
Is it
loud sounds that are the problem, or certain pitches/noises?
Does the sound actually cause physical discomfort to the dog (like it would in my ears if somebody scraped thier nails down a chalboard

) which makes it get stressed? If so, is there anything the vet can perscribe to help? Or is it a behavioural thing that needs desensitization?
Sorry for al the questions but the more details you can give, the better somebody can help.