Types of Hearing Disorders
The type and amount of hearing loss is different in every patient, so a hearing evaluation is important for accurate diagnosis and treatment planning.
The amount of hearing loss a child has can vary depending on his or her condition. Hearing loss also can affect a child’s ability to hear specific kinds of sounds, like low/deep pitches or high/sharp pitches.
Children with minimal hearing loss or hearing loss restricted to a specific pitch range may still respond to sounds in their environment. They may be able to turn when their name is called even though they can’t hear all the sounds of the words spoken.
Even mild hearing loss can cause difficulties with speech and language development. If you suspect your child has any amount of hearing loss, it is important to have a hearing evaluation, which will provide information about the amount and type of hearing loss so your child can receive proper treatment.
Types of Hearing Loss
Conductive hearing loss
A problem with sounds being sent through the outer and/or middle ear causes sounds to be muffled. This type of hearing loss may be a temporary problem caused by fluid behind the ear drum, an infection behind the ear drum, or a blockage due to wax or a foreign object in the ear canal. It may also be caused by a condition present at birth, such as an irregularity of the small bones of the middle ear. It may resolve with time, medication or surgical treatment. If it doesn’t resolve, hearing aids may be required.
Sensorineural hearing loss
This is caused by damage of the hair cells in the inner ear (called the cochlea). Patients with this type of hearing loss need sounds to be louder to be detected. Even when sounds are loud enough, they may not be clear enough to understand. This type of hearing loss can be congenital, meaning it is present at birth, or it can be acquired later. It is not typically resolved with medical treatment, and hearing aids are typically recommended for patients with this type of hearing loss.
Mixed hearing loss
This occurs when a patient has both conductive hearing loss and sensorineural hearing loss. Treatment may include a combination of medical intervention to resolve the conductive hearing loss and then hearing aids for the remaining sensorineural hearing loss.
Auditory neuropathy spectrum disorder
This is a less common type of sensorineural hearing loss in which the auditory nerve does not send messages to the auditory centers of the brain the same way every time. While the amount of hearing loss varies in each case, patients with this disorder perceive sound as distorted, which makes speech difficult to understand, especially in noisy environments. Treatment depends on the child’s developmental status and continued monitoring of his or her response to sound.
Central auditory processing disorder
Children with this disorder have normal hearing sensitivity but have difficulties processing or picking out the important information from what they are hearing. Children may have trouble listening when there is background noise, remembering a list of information they have heard, or picking out the important parts of what was said to them. Treatment focuses on improving the child’s processing skills and helping them develop strategies for dealing with difficult listening situations.
While every child is different, there are some common signs parents can look for to determine if their child's hearing is normal, or if he or she may need a hearing evaluation. Some examples of developmental milestones according to age are:
At birth to 3 months old:
- Startle or cry at loud noises
- Stop moving and appear to listen to speech or sounds
- Wake up at a loud sound
At 3-6 months old:
- Look toward a speaker or sound
- Smile when someone speaks to them
- Recognize their mother's voice
- Enjoy rattles and other toys that make noise
At 6-9 months old:
- Respond to his or her name
- Babble and make a variety of sounds
- Respond to the word "no"
At 9-12 months old:
- Turn or look when their name is called
- Listen to people who are talking
- Respond to simple commands like "give me" or "come here," and understand phrases like "bye-bye"
At 12-18 months old:
- Point to objects or familiar people by name
- Imitate simple sounds or words
- Follow simple spoken instructions
- Say 2-3 words by age 1 and 8-10 words by age 18 months
At 18 months to 5 years old:
- Hear and understand conversation easily
- Hear when they are called from another room
- Hear the television or music at the same volume as others, and hear quiet speech
- Have normal voice qualities, and normal verbal language development
- Show age-appropriate social and emotional development
For more information about our audiology services or to schedule an evaluation, please contact us.