In the outer ear:
Typical problems include excessive accumulation of earwax and infections of the auditory canal (e.g. ‘swimmer’s ear’).
In the middle ear:
Perforation of the eardrum, infection or fluid in the middle ear and otosclerosis (a calcification around the stapes limiting its ability to move) are the most common causes. Many outer and middle ear problems can be treated successfully with medication or surgery. In cases where treatment is not effective, remaining hearing loss can usually be helped by using hearing instruments.
In the inner ear:
The majority of hearing problems result from damaged inner ear structures. Typical causes are the natural aging process, excessive exposure to noise, medication that is toxic to the auditory system and head injuries. As a rule, this damage cannot be reversed but can be largely overcome with hearing instruments.
Degrees of hearing loss
Between the two extremes of hearing well and hearing nothing, there are many degrees of impairment. The terms used to describe the degree of hearing loss are mild, moderate, severe and profound. Most hearing losses are mild to moderate.What does the degree of hearing impairment mean?
Mild hearing loss
Unable to hear soft sounds and difficulty understanding speech in noisy environments.
Moderate hearing loss
Unable to hear soft and moderately loud sounds, considerable difficulty in understanding speech, particularly with background noise.
Severe hearing loss
Unable to hear most sounds. Speakers must raise their voice to be heard. Group conversation is possible only with considerable effort.
Profound hearing loss
Some very loud sounds are audible but communication without a hearing instrument or through sign language is very difficult.