The volume or loudness of a sound can be determined by the pressure level of the sound. The higher the pressure the higher will be the sound. Now this sound pressure level is measured in decibels (dB). The word “decibel” is derived from“deci” (meaning “one-tenth”) and the man who invented the decibel unit is Alexander Graham Bell.
Our hearing professional Categories hearing loss on the basis of their severity and degree of hearing loss. This severity is measured in decibels of hearing loss (dB HL). The categories of hearing loss are normal, slight, mild, moderate, moderately severe, severe-profound and deaf. It is based on frequencies of the sound need for you to hear sounds.
Types of Hearing Loss
- A conductive hearing loss is caused when the ear’s ability to conduct sound into the inner ear is blocked.
- Sensorineural hearing loss occurs from damage to an individual’s inner ear (cochlea) or neural areas of the auditory system.
- Mixed Hearing Loss goes literally by its name “mixed” and is a combination of conductive and sensorineural hearing loss.
- The least type of hearing loss is Neural hearing loss. It takes place when the auditory nerve is damaged, missing or transmits information to the brain incorrectly.
Sounds we hear in dB
- Quiet countryside: 20 dB
- low volume conversation: 40 dB
- Normal conversation: 60 dB
- Traffic noise: 80 dB
- Industrial noise: 100 dB
- loud music, like at a rock concert or nightclub: 120 dB
- Nearby thunder: 120 dB
- Jet engine: 140 dB
Classification of hearing loss dB in a person:
|Normal hearing||-10 to 15 dB|
|Slight hearing loss||16 to 25 dB|
|Mild hearing loss||26 to 40 dB|
|Moderate hearing loss||41 to 55 dB|
|Moderately severe loss||56 to 70 dB|
|Severe hearing loss||71 to 90 dB|
|Profound hearing loss||91 to 120 dB|
|Deaf greater than||120 dB|
Mild hearing loss: People suffering from mild hearing loss hear sounds between 25 to 40 dB. They get difficulty in conversations, especially in noisy environments.
Moderate hearing loss: Moderate hearing loss suffering individual hear a sound at 40 to 70 dB or more. They get difficulty in hearing without using a hearing aid.
Severe hearing loss: Affected people hear sound between 70 to 95 dB. They can’t hear sound with a normal hearing aid and need a powerful hearing aid.
Profound hearing loss: people hear a sound at 95 dB or more. They mostly communicate with sign language and lip-reading.
Understanding language and speech, the possible effects of hearing loss can be given below:
16-25 dB Hearing Loss:
- Compared to the ability to hear the index finger on the ear.
- Difficulty hearing faint or distant speech.
- At 16 DB hearing loss, the child can remember up to 10% of the speech signal when a speaker is at a distance of more than 3 feet. Whenever there will be background noise, the missed speech will be more.
26-40 dB Hearing Loss:
- The child can “hear”, but misses a piece of speech due to misunderstanding.
- At 30 dB hearing impairment, the child can remember 25-40% speech sign.
- At 40 dB, the child can remember 50% of the class discussions.
41-55 dB Hearing Loss:
- 50 dB hearing loss may be remembered by up to 80% of the speech signal in the child.
- Even with hearing aids, if there is background noise, the child will miss much of what is being said.
56-70 dB Hearing Loss:
- Without amplification, the child misses up to 100% information of the speech due to hearing loss of 55 dB.
71-90 dB Hearing Loss:
- Without amplification, 71-90 DB of hearing impairment can only hear about 1 foot high sound from the ear.
- A child with a hearing loss of more than 70 dB may be a candidate for cochlear transplantation. A child with hearing loss greater than 90 dB will not be able to feel most speech sounds with traditional hearing aids