Hearing impairment is a disorder that deals with the decreased ability to hear. It is said that the disorder is one of the most common birth defects. Every year about 12,000 infants are born with this disorder in the United States.

Hearing impairment that are present in a child since the time of his birth is called congenital hearing impairment. Hearing impairment also can develop when a child grows up or during his adulthood.

Normal hearing thresholds are different for all frequencies in all kinds of living beings. In an experiment different frequencies of certain sound effects were played keeping in position a similar amplitude, and it was observed that some were very loud, and others were very low and quiet and some were completely inaudible. And it is actually true also.

And if the amplitude is increased, then it is likely that the sound is more likely to be perceived. In general when animals use certain sounds in order to communicate, hearing in that type of animal becomes so very sensitive for the frequencies that are actually produced or released by calls, or, in the case of living beings, what we call as speech.

This tuning of hearing is available at a lot of different levels as far as the auditory system is concerned,
 all the way from the physical aspect of the ear that leads to the nerves and tracts. These are actually responsible for conveying the nerve impulses of the auditory portion of the brain.


The hearing impairments can be a result of physical conditions such as childhood illnesses,  injury, heredity, age, pregnancy-related illnesses, large or prolonged exposure to noise, and can result in different degrees of hearing loss. Generally, the disorder id divided into as mild, moderate, severe, or profound.

An individual who is suffering from mild hearing impairment may hear few sounds but not accurately, he may face a lot of difficulty in distinguishing specific speech patterns that are implemented in a lot of conversation.

Hearing loss can result from inheritance.

Dominant gene as well as recessive genes are present in our body which can be responsible for causing mild to profound impairment. If someone has a family history of dominant gene for deafness then there are chances that the disease will persist across generations. The statement is because of the fact that  it will manifest itself in the offspring even if it is inherited from only one parent.