Hearing Loss in Adults
What Is Hearing Loss?
Hearing loss refers to a partial or total inability to hear. It can result from problems with the ear (outer, middle, and/or inner), the vestibulocochlear nerve (i.e., cranial nerve eight or CN VIII), and/or the auditory system. In the context of this page, hearing loss refers to an audiologic diagnosis of hearing thresholds outside the range of typical hearing.
Hearing loss has a variety of causes and may be:
- Bilateral or unilateral
- Symmetrical (degree and configuration of hearing loss are the same in each ear) or asymmetrical
- Progressive or sudden onset
- Fluctuating or stable
- Present at birth or acquired at some point during an individual’s life.
Hearing loss can be described by variations in type, degree, and configuration. The three basic types of hearing loss are sensorineural, conductive, and mixed.
- Sensorineural hearing loss is due to cochlear (sensory) or vestibulocochlear nerve/CN VIII (neural) auditory dysfunction.
- Conductive hearing loss is due to a problem conducting sound waves through the outer ear canal, tympanic membrane, or middle ear (ossicles).
- Mixed hearing loss is the result of damage to conductive pathways of the outer and/or middle ear and to the nerves or sensory hair cells of the inner ear.
The degree of hearing loss refers to the level of severity. The degree of hearing loss can have significant implications for an individual (e.g., limiting the ability to understand speech in background noise, decreasing the enjoyment of music, and impacting overall quality of life).
The table below shows one commonly used classification system.
Degree of hearing loss | Hearing loss range (in dB HL) |
Normal | –10 to 15 |
Slight | 16 to 25 |
Mild | 26 to 40 |
Moderate | 41 to 55 |
Moderately severe | 56 to 70 |
Severe | 71 to 90 |
| Profound | 91+ |
| Note. dB HL = decibels in hearing level. Adapted from Clark (1981). | |
The configuration, or shape, of the hearing loss, refers to the pattern of hearing loss across frequencies, as illustrated in a graph called an audiogram. For example, flat hearing loss configurations indicate approximately the same amount of hearing loss for low and high frequencies, whereas the configuration for a high-frequency or a low-frequency loss will appear sloped.
The assessment, treatment, and management of hearing loss and related disorders is often an interprofessional process. Audiologists, Speech Therapists, otolaryngologists, primary care physicians, and various other specialists may be involved.
An individual with hearing loss and their family (which includes, for the purpose of this page, family members, significant others, caregivers, and support system members) are integral to the assessment, treatment, and management process, including planning, decision making, and service delivery. Comprehensive hearing health provision models include person- and family-centered approaches.
Speech Therapists can assist those who have hearing impairments by offering strategies focused on improving communication, such as lip reading and providing hearing aid instruction interventions. At Persian Speech Clinic, individuals with Hearing Loss can receive Speech Therapy for their communication difficulties, language development, verbal communication, cognitive skills, and learning abilities. Early intervention is a key to improve communication skills and to prevent language and speech disorders.