Please share the audiometry reports for any further opinion. Autophony is usually due to conductive type of hearing loss. Which may occur from external ear cause like wax or middle ear issues like accumulation of water or pus in the middle ear. It can also be due to eustachian tube dysfunction. A hearing test called impedance audiometry or tympanometry will show these conditions. Steam inhalation twice a day will help you to get the relief till these tests are done and u consult a doctor for the final treatment