Hearing loss - Background

Hearing loss is a common phenomenon. According to the Royal National Institute for the Deaf (RNID), 1 in 7 people suffer from a hearing disorder.

More than 50% of people over 60 years old have a hearing impairment. Hearing impairment is the second most common cause of disability in older people.

There are many causes of hearing loss. The common cause is the aging process and other causes include hereditary problems, diseases, infection, certain drugs and injury, and exposure to excessive loud noise.

A Hearing test can be done at any age to assess the degree of hearing loss.

About Sounds and Hearing test:

Sounds vary based on their loudness (intensity) and the speed of sound wave vibrations (tone).
Hearing occurs when sound waves are converted into electrical energy, which stimulates the nerves of the inner ear. Those sounds travel along nerve pathways to the brain.

The INTENSITY of sound is measured in decibels (dB):

• 
  A whisper is about 20 dB
• 
  Loud music is around 80 - 120 dB

The TONE of sound is measured in cycles per second (cps) or Hertz:

• 
  Low bass tones range around 50 - 60 Hz
• 
  Shrill, high-pitched tones range around 10,000 Hz or higher

The normal range of human hearing is about 20 Hz - 20,000 Hz.
A hearing test provides an evaluation of the sensitivity of a person's sense of hearing and is performed by an audiologist.