let me answer your concerns
1. the cyst
in the pituitary gland
will not cause your hearing loss
. both are different problems.
2. in view of the cyst in the pituitary gland, you need get your hormone levels evaluated , do see a endocrine doctor/physician for the same .
3.kindly post in your pure tone audiogram results ( hearing tests)
i hope this helps , please do ask if you need any further clarification.