What are Causes of hearing loss Outer & Middle Ear

Many different conditions can cause hearing impairment, and the cause can be located in any part of the system. At any age, hearing can be damaged gradually or suddenly. Hearing impairment knows no age limits. More often a hearing loss is gradual and painless, in many cases developing so slowly it is barely noticeable.
Your ability to hear is as unique as your fingerprint. Similarly, no two people have exactly the same hearing impairment.
Workplace noise inherited medical conditions, childhood and adult illness all combine to produce different types of hearing losses in different people. For example, some people will hear all sounds, but it is as though the volume is turned down. For others, speech and music sound slightly distorted. Another group finds it difficult to hear specific sounds such as conversation in a noisy room or environment.
Hearing impairment can result from the disruption of normal functioning anywhere along with the auditory system. Some of the major causes of hearing impairment are continuous colds, hereditary factors, severe diseases which affect the auditory nerve, allergies, loud noises, obstructions in the external auditory canal, advancing age, a blow to the ear, some drugs and high fever.
Hearing Loss Causes:

• Outer ear causes
• Middle ear causes
• Inner ear causes
• Central hearing disorder

Causes of Outer Ear hearing loss

Problems of the outer ear cause a "conductive" hearing loss. This simply means that something is blocking the sound from being effectively conducted to the inner ear. The following describes some of the more common causes of hearing impairment.

• Wax  buildup can block the auditory canal, preventing sound from entering. Although it does not always cause hearing problems, it may be an annoyance. This is a common cause of outer ear problems. Periodic removal of the wax by a physician usually will help.
• Infection of the skin lining the auditory canal (external otitis) can cause itching, rawness or swelling. A condition called "swimmer's ear" can be one such condition. These do not usually cause hearing loss but may lead to more serious infections unless treated. Medication recommended by a physician can usually clear up the condition.
• A malformation of the ear canal or the insertion of foreign objects into the ear canal can cause a hearing loss.

Causes of Middle Ear hearing loss

• Middle ear infection, called otitis media, is a result of the formation of fluid from the middle ear lining. The severity will vary, with pus-forming and settling in the middle ear cavity, and often causing hearing loss. The loss is usually temporary, but may become permanent and pose a serious health threat without medical treatment. Middle ear infections may result from allergies, head colds, inflamed tonsils and adenoids, blocked Eustachian tubes, sore throats or other viruses.
• A ruptured eardrum or hole in the eardrum can result from a variety of causes, including extreme air pressure changes in the auditory canal (i.e. flying or underwater), from a blow to the ear, cleaning the ear with a sharp instrument, or from pressure as a result of a buildup of fluid due to infection in the middle ear. A rupture of the eardrum could produce a hearing impairment, cause scarring of the eardrum, and may also damage the tiny middle ear bones.
• Immobilized middle ear bones (otosclerosis) results from deposits forming between the stapes and the opening in the inner ear where it moves in and out. This restricts or immobilizes the lever action, resulting in significant hearing impairment. Surgery is helpful in many cases.
• Unhinging of the middle ear bones may occur. 

Other middle ear disorders, such as otosclerosis, the growth of tumors in the middle ear space, and abnormalities developed before birth can also cause hearing problems.
Hearing impairment to the outer and middle ear, which are caused by blockage of the sound to the inner ear, or are caused by mechanical restriction, are called conductive hearing losses. The degree of hearing loss is variable, but these problems can usually be helped by medical and/or surgical attention.

A conductive hearing loss is usually characterized by:

• A  person who speaks softly. We monitor our own voices by what we hear when we speak. Because a conductive hearing loss blocks out external noises, the person thinks he is speaking loudly enough and doesn't raise his voice in noise, as normal hearing people do.
• Hearing well in noisy settings because others raised their voices to overcome the external noise. Because understanding is good (no hair cell damage), the louder voices help overcome the loss of hearing.
• A hearing loss that produces an overall reduction of sound across part or all of the hearing range. Speech sounds become unclear because the sound is not loud enough. If it could be made louder, understanding would occur. (This is a major difference between conductive and sensorineural hearing loss).
• A blockage of sound to the inner ear rather than damage to neural structures.
• A loss that is usually temporary, but which can overcome permanent, especially when not medically treated.
• More common in children.