WHAT IS AN AUDIOLOGIST?
An audiologist is a university-trained professional, who specializes in assessment of hearing and balance disorders. To obtain licensure in the State of Nevada, an audiologist must have an advanced degree in audiology, either a Master of Science or Doctoral degree, and hold the Certificate of Clinical Competence from the American Speech-Language-Hearing Association.
Sierra Hearing Center’s audiologists are also licensed to dispense hearing aids in the State of Nevada.
HOW WE HEAR
Hearing and understanding speech are important aspects of human communication. Normal ears can perceive: 1) different pitches ranging from 20 to 20,000 Hertz, 2) loudness ranging from very soft (0 dB HL) to painfully loud (100 dB HL), and 3) the sound’s location. The ear is composed of three sections: the outer, middle and inner ear. Each section has a specific function during the hearing process.
The outer ear gathers sound waves and directs them through the ear canal toward the eardrum. The eardrum vibrates, setting three middle ear bones in motion. This motion is transferred to the fluid filled cochlea (organ of hearing), stimulating special hair cells in the inner ear. The hair cells send impulses to the auditory reception area of the brain.
For a more detailed description of human hearing visit: www.hear-it.org
TYPES OF HEARING LOSS
According to the National Institute on Deafness and Other Communication Disorders, 30 million Americans have some form of hearing loss (National Library of Medicine, October 2000). A hearing loss exists when sound transmission is disrupted anywhere along the hearing pathway. There are three types of hearing loss: Conductive, Sensorineural, and Mixed. A comprehensive hearing evaluation is necessary to determine type of hearing loss.
CONDUCTIVE HEARING LOSS
When a sound cannot be transmitted through the outer or middle ear, a conductive loss is present. This type of hearing loss may result from problems such as impacted earwax (outer ear) or an ear infection (middle ear), to name a few.
SENSORINEURAL HEARING LOSS
When sound cannot be transmitted through the inner ear and/or neural pathway, a sensorineural loss is present. This type of hearing loss may result from damage to hair cells in the inner ear or along the auditory nerve (neural). Aging and noise exposure are two factors that can lead to damage or loss of hair cells. This accounts for approximately 95% of hearing impairments.
MIXED HEARING LOSS
Hearing losses resulting from both conductive and sensorineural components are diagnosed as having a mixed loss.
For more information about types of hearing loss visit: www.asha.org/hearing/testing/assess.cfm
DEGREE OF HEARING LOSS
No two hearing losses are the same. Hearing loss may result from a variety of causes, occur in one or both ears, and vary in type and severity. The degree of loss determines what effect the hearing loss will have on communication. Degree of hearing loss is placed in one of four categories: mild, moderate, severe, and profound.
A person with a mild hearing loss has responses between 25 and 40 dB HL. People with mild losses have problems hearing very soft and distant sounds. The mild hearing impairment may interfere with understanding speech.
Individuals in the moderate category have hearing levels between 40 and 60 dB HL, while individuals in the severe category have hearing levels between 60 and 80 dB HL. People with either moderate or severe hearing losses will experience difficulty understanding speech, especially when background noise is present. These individuals frequently say that people mumble, avoid conversations, turn the television up too loud for others’ comfort, and may not even know that people are speaking to them.
Profound losses are those with responses above 80 dB HL. Individuals with profound losses cannot depend solely on their hearing for communication. They often depend on vision and/or gestures to communicate. People with profound losses may not hear any sound around them without an assistive listening device.
NOISE INDUCED HEARING LOSS
Even at a young age, exposure to noise can lead to irreversible hearing loss. Twenty-five million Americans are exposed to noise in the workplace. Recreational noise exposure from guns, power tools, music, motorcycles, and toys is also quite common. Exposure to noise levels of 85 dB or more may have permanent detrimental effects on hearing.
For example, loud music at a concert can reach loudness levels as high as 110 dB. It only takes 30 minutes of exposure to this level of noise to damage the hair cells responsible for the sense of hearing. Ringing in the ears, temporary hearing loss, and permanent hearing loss are indicators that damage has occurred.
There is no cure for noise-induced hearing loss. However it can be prevented. Hearing protection is available in many styles including foam earplugs, custom earplugs, and earmuffs. Sierra Hearing Center is proud to offer a complete line of custom hearing protection for work or leisure needs.