There are three types of hearing loss that are categorized according to where the damage or malfunction occurs. These three types of hearing loss can vary in severity and may be unilateral (in one ear) or bilateral (in both ears).
Types of Hearing Loss: ConductiveConductive hearing loss results from an interference or blockage of the outer or middle ear structures. Sound cannot get through to the inner ear or is significantly reduced before it does.
Common causes include abnormal development of the outer or middle ear, injury and blockage due to ear wax or chronic middle-ear infection. In most cases, this type of hearing gloss can be corrected with medical intervention.
Sensorineural Hearing Loss
This is the most common type of hearing loss. It occurs when the hair cells inside the cochlea are damaged and therefore unable to transform sound vibrations into electrical signals. Common causes include genetic defects, noise exposure, ototoxic medications, viral infections and/or degeneration of the inner ear and auditory nerve pathway due to aging. The hearing loss is typically permanent and cannot be reversed by medical intervention. This type of hearing loss can be helped with hearing aids.
Mixed Hearing Loss
Mixed hearing loss occurs when a patient exhibits a combination of conductive and sensorineural hearing losses. Treatment for this type of loss includes medical intervention to correct the conductive component and amplification to treat the sensorineural component.
Treating Hearing Loss
Over the last decade drastic improvements have been made by manufacturers to improve hearing aid technology and thus performance, particularly with the development of dual-microphones and digital technology to assist with speech understanding in noisy environments. It is also true that hearing aid satisfaction and acceptance has improved, especially in the last 5 years. The problem still remains: hearing aids cannot restore normal hearing. Particularly we find that hearing aids have limited abilities in the case of sensorineural hearing loss (damage to the inner ear nerve), because the damaged nerve results in distortion of sounds as well as a need for more volume or amplification of sounds.
Conductive hearing loss, if untreatable by medical intervention, is typically a problem that can be addressed by amplification without distortion because the auditory nerve of the cochlea is still intact. Therefore, no matter what type or degree of hearing loss, if medically untreatable, hearing aids are the necessary first step in hearing sounds again. If sounds are not audible or heard, there is no way understanding can occur. The distortion component of sensorineural hearing loss is the most common complaint among hearing impaired listeners, “I can hear, I just cannot understand.”
Common statements from hearing impaired listeners include:
- It sounds like people are mumbling.
- If people would just enunciate, I could understand them.
- People just don’t talk right; they need to look at me if they want to talk to me.
- It’s not that I can’t hear people speak, their speech is just not clear.
The devastating effects of hearing loss are sometimes unnoticed because hearing loss is considered an invisible disability. This means hearing loss is a disability, but not a disability that anyone would notice just by looking at you. Take for instance, visual impairments. If you see someone in glasses struggling to read a flight itinerary, you might ask them if you can help or if a person in a wheelchair was entering a restaurant in front of you, you might rush ahead to open the door for that person; however, if a person with hearing loss did not hear the flight announcement or worse yet, did not even know there was an announcement, how would you know to help that person?
For this reason, many individuals with hearing loss will change their lifestyle as their hearing changes. Changes may include isolation from friends, family or events due to fear, such as inability to participate in conversation. A hearing impaired person might also dominate the conversation because if someone else speaks, he/she will not understand what is said. In treating hearing loss, obtaining hearing aid systems is the necessary first step. The information in this section will assist you in teaching effective communication strategies to patients who have received hearing aids or are in the process of being fit with hearing aids.