There are four types of hearing loss: conductive, sensorineural, mixed and auditory
neuropathy. All can be either congenital or acquired.
Congenital means the child is born with hearing loss. Acquired
means the hearing loss happens after birth.
There are also five degrees of
hearing loss: mild, moderate, moderately
severe, severe and profound.
Children will have either
unilateral hearing loss or bilateral hearing loss. Unilateral means
only one ear has hearing loss. Bilateral means both ears have
Types of Hearing Loss:
When sound does not move clearly through
the outer and middle ear to the inner ear, it is called conductive
hearing loss. In most cases, the problem can be fixed with medical
help, but sometimes it can be permanent.
Usually, an ear infection causes temporary conductive hearing
loss. When an infection or fluid blocks the middle ear, the eardrum
and the bones cannot vibrate like they should. This stops
sound from getting to the inner ear and causes the child to have
Sometimes a middle ear infection is not the cause of conductive
hearing loss. Too much ear wax, damaged middle ear bones, and
abnormal middle or outer ears can also cause this type of hearing
loss. In these cases, the child can wear hearing aids to hear
Problems with the inner ear or the
auditory nerve are called sensorineural hearing loss. Damage to
the inner ear comes in different degrees: the more damage,
the more hearing loss.
pitches may be affected more than others. This type of
hearing loss usually leads to problems with hearing soft
sounds and problems with understanding speech.
sensorineural hearing loss:
Sensorineural hearing loss is
permanent. Usually, it cannot be treated medically. However,
it can be treated with
amplification and hearing aids.
Depending on the level of hearing
loss and the pitches that are affected, the audiologist
may suggest that the child try hearing aids. However, hearing
aids are not like glasses; they will not give a child normal
hearing. Hearing aids may help make some sounds heard that were not
heard before but making sound loud enough does not always make
sound easier to understand. With hearing aids, speech may still
sound distorted to the child, because hearing loss affects the
inner ear in different ways.
Some children have hearing loss in
both the middle (conductive) and the inner ear
(sensorineural). This is called mixed hearing loss.
Spectrum Disorder (ANSD)
Auditory neuropathy spectrum disorder
(ANSD) is also called auditory neuropathy or auditory
If a child has this type of hearing
loss, sound is entering the
cochlea like normal, but the nerve that is supposed
to send signals to the brain (the
auditory nerve) is not working right.
This causes children to have a wide
variety of problems with hearing. Some may have mild problems;
others severe. Some children may have problems hearing and
understanding sounds, need visual cues to understand a
conversation, or have delays with speech and language. This is why
auditory neuropathy is called a spectrum disorder: no two children
with ANSD are exactly alike and not all will have the same
Degrees of Hearing
With mild hearing loss, children
cannot hear sounds softer than 25-40
decibels (dB). An example of sound they cannot hear is
whispering, which is around 40 dB. They also cannot hear some soft
speech sounds even when spoken at a normal level. Some sounds they
may have a problem hearing are /s/, /f/, and /th/.
If a child does not get a hearing
aid or implant to increase sound or is not helped early in
life, the hearing loss can cause inattention, language delays
and speech problems. Sounds that are somewhat loud to a normal
hearing person, such as speech, will sound like a whisper to
With help, such as hearing aids and
therapy, most children can understand the soft sounds of
speech and the world around them.
Sounds softer than 40-55
dB cannot be heard by children with moderate hearing
Without help, most speech sounds
will not be heard. Sounds that are loud to a normal hearing
person will be a whisper to the children. They will only
understand speech if it is loud. Children may have errors
in their speech. They may not pay attention and may have
speech, language and learning problems. An adult may have a hard
time understanding the child.
With help, most children can understand
soft sounds of speech. Most children will develop vocabulary,
language understanding and talking. Most children will learn
to speak clearly if they wear hearing aids everyday, all day.
Children with this degree of
hearing loss have problems hearing sounds softer than 55-70
dB. An example of a sound at this level is a
dishwasher (60 dB).
Without help, children with
this amount of hearing loss can hear and
understand a loud voice very close to them. They
usually do not develop speech and language on their own, and if
they do, their speech will be poor.
Hearing aids will help these
children hear conversation. If the children get speech and
language therapy, they can understand and make most speech
With severe hearing loss, children
cannot hear sounds softer than 70-90
dB. Examples of a sounds they may not hear are a
vacuum (70 dB), or a blender and a hairdryer (90 dB).
Without help, the child will have
problems understanding most speech sounds. Other loud sounds may
not be heard at all. The child will hear no speech sounds at normal
conversation level. Sounds that are very loud to a normal hearing
person will be very soft to the child. Speech will only be heard if
it is shouted in the child's ear. A child with this degree of
hearing loss will have speech that is not understandable.
With the help of hearing aids or
implants and therapy, children with this degree of hearing
loss often can understand most sounds. They
can learn to understand and speak, even though they will not
hear speech the way children with normal hearing do. Most
children will need help in school to make up for problems
they have with hearing in noisy places or hearing far away
Children with profound hearing
loss cannot hear sounds softer than 91
dB. Examples of this are MP3 players with the volume
turned up all the way (100 dB) and car horns (110 dB).
These children must
have special education to help them learn language and speech.
Without this help, children cannot hear sounds. They use sight
instead of hearing to communicate. People with normal hearing
cannot understand their speech.
However, technology and therapy can
help children with profound hearing loss. With a hearing aid or
cochlear implant, many children will hear loud sounds and spoken
conversation if there is no background noise and they are facing
the speaker. Many children still need to use visual cues (read
lips, see facial expressions, etc.) to help them understand spoken
conversation. Most children with a profound hearing loss also need
help at home and school to improve their speech and language.