Types of Hearing Loss
What is hearing loss?
If your child has been diagnosed with hearing loss, it means that something with your child’s ears, the nerves that come from the ears, or the part of the brain that controls hearing is not working as well as it should.
Hearing loss can range from mild, where only some sounds are not heard, to profound, where nothing is heard. No matter the severity of the hearing loss, it can affect your child’s educational and social development in significant ways.
Approximately 2 to 4 of every 1,000 babies are born with some degree of hearing loss, making it one of the most common birth defects.
Types of hearing loss
Conductive Hearing Loss occurs when sound is blocked or reduced as it travels to the inner ear. This may be due to an obstruction or abnormality of the outer or middle ear. Once sound reaches the inner ear, hearing is within normal limits. A conductive hearing loss may be medically treated, but an evaluation by an ear, nose and throat (ENT) doctor will be necessary to determine the cause of the conductive hearing loss.
Sensorineural Hearing Loss (SNHL) occurs when there is damage to the inner ear (cochlea), or to the nerve pathways from the inner ear to the brain.This is the most common type of permanent hearing loss. Even when speech is loud enough to hear, it still may be unclear or sound muffled.
Mixed Hearing Loss is a combination of a conductive hearing loss and sensorineural hearing loss. A mixed hearing loss occurs when sound is unable to be transmitted from the outer or middle ear to the inner ear normally, and there is damage to the inner ear (cochlea) or auditory nerve.
Auditory Neuropathy Spectrum Disorder (ANSD) is when the cochlea receives the sound, but the auditory nerve carries jumbled electrical signals to the brain (dyssynchrony). This means that instead of a smooth transition of information from the cochlea to the brain, the signals are not timed correctly so information is not relayed to the brain in a consistent manner. The amount of dyssynchrony can vary from person to person and can fluctuate in an individual over time. Children may have normal hearing or hearing loss ranging from mild to profound which may fluctuate from day to day.These children have difficulty understanding speech clearly, especially in the presence of background noise.
Causes of hearing loss
About 50% of hearing losses present at birth (congenital hearing loss) is caused by genetic factors passed down from one or both parents. In many cases, a child’s hearing loss may exist alongside other conditions as part of a syndrome.
Another 25% of congenital hearing losses occurs because of environmental factors during pregnancy or birth.These hearing losses may stem from an infection contracted during pregnancy (such as cytomegalovirus or rubella), a lack of oxygen (anoxia), or issues related to low birth weight and prematurity. Hearing loss may also be caused by lifesaving medications given to infants in the NICU or from acquired infections, like meningitis.
The remaining 25% of congenital hearing losses are idiopathic, which means the cause is unknown.
Important next steps
Otologic Evaluation - Following the diagnosis of hearing loss, your child must see an Ear, Nose & Throat (ENT) doctor to obtain clearance for appropriate hearing technology.
Hearing Aid Evaluation - A hearing aid evaluation with a pediatric audiologist is necessary to determine the best hearing technology for your child. Fitting your child with hearing technology as soon as possible following the diagnosis of hearing loss is extremely important for your child’s overall hearing, speech and language, and brain development.
Speech & Language Evaluation - A speech and language evaluation by a therapist trained in working with children who have hearing loss is essential to monitor development. With appropriate intervention, your child has the opportunity to develop listening, speaking and literacy skills on par with hearing peers.
SPOKEN LANGUAGE METHOD: Teach a child to speak and listen through hearing.
Main Goal: Diagnose hearing loss and fit child with hearing technology as soon as possible. Family members are active participants in the therapy process. Child is enrolled in a mainstream educational setting.
- Uses hearing to teach listening and talking.
- Does not use sign language or lipreading.
- Use hearing and lipreading.
VISUAL METHOD: Teach a child sign language as the primary mode of communication.
Main Goals: Provide communication and access to the Deaf community. Provide a basis for learning spoken and written English as a second language.
American Sign Language (ASL)
- A visual language that has its own grammar and linguistic codes.
Conceptually Accurate Signed English (CASE)
- Use signs from ASL in the same order of English sentences.
COMBINED APPROACHES: Use sign language and speech to communicate.
There are several options for a person with hearing loss to choose from to communicate with their family, peers and the rest of the world.
All methods require a commitment on your part in order for you to be able to communicate with your child.That daily commitment to communicating is the key to your child’s language development. Schedule an appointment to discuss your child’s communication options.
Decisions involving communication options impact not only your child’s future, but that of your entire family. Remember to include your whole family when making decisions about the best options for your child with hearing loss.
Total Communication Method
Main Goal: Participate in both hearing and Deaf communities. Use many forms of communication:
- Sign language used in total communication is not a language in and of itself, like ASL, but follows the grammatical structure of English.
- Includes speaking, speech reading, amplification and finger spelling.
Main Goal: To teach a child to speak and listen through hearing and speech reading.
- Use auditory and visual information.
- Eight hand cues around the face in combination with natural mouth movements to clarify spoken language.