Hi
Oral candidal infection is not likely to interfere with BERA test as it bypasses the possible interfering outer ear structures and measures directly the status of
inner ear and
nerve connections above to brain.
If you feel that your child can hear without
hearing aid please get his hearing checked by paediatric
audiometry or if it is not conclusive BERA test itself. This is likely to clear your doubt. After this if it is sure that he can hear well without aids then no need to use it.
Even with this if it is not explained show hm to a good
ENT specialist in your area who can solve the problem.
Take care.