Many professionals who work with children can feel confused when it comes to understanding different types of hearing loss. For example, if a health record indicates that a child has a "fluctuating conductive" hearing loss, what does that mean? How is that different from a "sensorineural" hearing loss?
These are questions that Head Start staff find themselves asking as children identified through screening go on for audiological assessment. Having a working knowledge of several terms used to describe hearing loss will allow you communicate with the audiologist and assist the family in understanding appropriate intervention options.
Hearing loss can be caused by problems in the outer, middle or inner ear.
Although a health care provider can often identify common problems in the outer and middle ear, the diagnosis of how much impact the specific condition has on hearing is made by an audiologist.
When an outer or middle ear condition causes a hearing loss, it is called a "conductive" loss. This means that the sound waves are weakened as they move through the outer and middle ear on their way to the inner ear.
Conductive hearing loss is commonly associated with wax blockage in the ear canal, fluid in the middle ear caused by infection (otitis media), or a perforation (hole) in the eardrum. When a child has otitis media, and the middle ear alternately fills with fluid and then clears, the hearing loss is called "fluctuating conductive." This type of loss is generally temporary, or transient, and can be treated with medicine or pressure equalization (PE tubes). But if the problem continues for a long period of time, or recurs repeatedly, it can have a negative impact on a young child's language development. Although much less common, malformation in the three small bones in the middle ear that transmit sound from the outer ear to the inner ear can also cause a conductive loss. This would result in a "permanent conductive" hearing loss unless treated surgically.
When there is a problem in the inner ear (cochlea), it is called a "sensorineural" hearing loss. This type of loss can be caused by genetic factors, head trauma, or certain infections. Health care providers cannot visually observe a cochlear abnormality, and because this type of loss cannot be corrected medically--it is "permanent." That's why hearing screening for all children, and follow-up for those who do not pass, is so important.
The degree of loss can range from mild, where the child can hear many environmental sounds but cannot hear quiet speech, to severe or profound, where the child cannot hear any speech, and may not even be able to hear very
loud sounds. Even though sensorineural hearing loss is permanent, in most cases amplification, such as hearing aids or cochlear implants, along with therapy, can help a child to hear and understand speech. When a child has a permanent loss, some families choose to learn sign language to communicate.
It is also possible for a child to have a sensorineural hearing loss along with a conductive loss. This is usually referred to as a "mixed" hearing loss. Making the issue even more complex, a hearing loss of any type can occur in both ears (bilateral) or only one ear (unilateral).
You don't need to become an expert in all the configurations of hearing loss, but having a basic understanding of why a loss is considered permanent or temporary will help you to communicate effectively with other professionals, and will allow you to support parents in seeking appropriate treatment/intervention options.
