Disabling hearing loss refers to hearing loss greater than 40 decibels (dB) in the better hearing ear in adults and a hearing loss greater than 30 dB in the better hearing ear in children.

A person who is not able to hear as well as someone with normal hearing – hearing thresholds of 25 dB or better in both ears – is said to have hearing loss.
Hearing loss may be mild, moderate, severe, or profound. It can affect one ear or both ears, and leads to difficulty in hearing conversational speech or loud sounds.
World Hearing Day is celebrated on 3rd March every year. Some facts about deafness:
466 million people in the world live with disabling hearing loss. It is over 5% of the world's population. It includes 432 million adults and 34 million children.
It is estimated that by 2050 over 900 million people – or one in every ten people – will have disabling hearing loss.
3.60% of childhood hearing loss is due to preventable causes.
1.1 billion young people (aged between 12–35 years) are at risk of hearing loss due to exposure to noise in recreational settings.
Approximately one third of people over 65 years of age are affected by disabling hearing loss.
Approximately 70 million deaf people use sign language
The number of adults 20 years or older with some kind of measurable hearing loss will climb from 44 million people in 2020
South Africa has highest number of deaf persons in the World.
New Jersey has the lowest number of deaf persons in the World.
Quintus Pedius of Rome is the earliest deaf person in recorded history known by name.
Dewey Lynn Bridgman is known as the first educated deaf and Helen Keller was the second.
First person credited with the creation of a formal sign language for the hearing impaired was Pedro Ponce.
First word that Helen Keller was taught was water. 03 in 1000 babies are born with some kind of hearing loss. There are 63 million deaf persons in India.