What is a Hearing Instrument Specialist?
A hearing instrument specialist (HIS) is a professional trained specifically in the fitting of the hearing aids and assistive listening devices. A hearing instrument specialist has extensive supervised on-the-job training prior to being licensed by the state. The hearing instrument specialist is required to fulfill annual continuing education requirements.
What Types of Tests and Treatments do Hearing Instrument Specialists Perform?
Common services and treatments provided by a Hearing Instrument Specialist include:
- Hearing aid fitting
- Hearing tests and evaluation
- Hearing aid repair
- Assistive listening devices
How Do I Know if I Have Hearing Loss?
If you think you or a loved one may have hearing loss, you are not alone. Often times people notice signs of hearing loss but do not take the steps to get it treated right away. Typically, it takes people an average of seven years to seek treatment. You may have hearing loss if:
- You hear people speaking but you have to strain to understand their words.
- You frequently ask people to repeat what they said.
- You don’t laugh at jokes because you miss too much of the story or the punch line.
- You frequently complain that people mumble.
- You need to ask others about the details of a meeting you just attended.
- You play the TV or radio louder than your friends, spouse and relatives.
- You cannot hear the doorbell or the telephone.
- You find that looking at people when they speak to you makes it easier to understand.
- You miss environmental sounds such as birds or leaves blowing.
- You find yourself avoiding certain restaurants because they are too noisy, or certain people, because you cannot understand them.
- You hear a ringing sound in your ears, especially when it is quiet.
What Causes Hearing Loss?
Hearing loss can be due to several factors such as the aging process, exposure to loud noise, medications, infections, head or ear trauma, congenital (birth) or genetic factors, diseases, as well as a number of other causes. Recent data shows that about 20 percent of adults in the United States (48 million) report some degree of hearing loss. Hearing loss often occurs gradually throughout a lifetime.
How is Hearing Loss Diagnosed?
If you have any symptoms of hearing loss, you should see a hearing instrument specialist to have a formal hearing evaluation. This hearing test allows the hearing instrument specialist to determine the type, nature and degree of your hearing loss and provide an indication as to how successful of a candidate you will be for hearing aids.
The hearing evaluation will also include a thorough case history and a visual inspection of the ear canal and eardrum. The results of the evaluation can be useful to a physician, if the hearing instrument specialist believes your hearing loss may benefit from medical intervention.
Results of the hearing evaluation are plotted on a graph called an audiogram. The audiogram provides a visual view of your hearing test results across various pitches or frequencies, especially the ones necessary for understanding speech.
The audiogram and results from your speech understanding tests are used to create a prescription by which hearing aids are programmed, if necessary.
What Are There Different Degrees of Hearing Loss?
After you undergo a hearing evaluation, the results are plotted on a chart called an audiogram. Loudness is plotted from top to bottom. The top of the graph is very quiet and the bottom of the graph is very loud. Frequency, or pitch, from low to high, is plotted from left to right. Hearing level (HL) is measured in decibels (dB) and is described in general categories, not by percentages. The general hearing loss categories used by most hearing professionals are as follows:
- Normal hearing (0 to 25 dB HL)
- Mild hearing loss (26 to 40 dB HL)
- Moderate hearing loss (41 to 70 dB HL)
- Severe hearing loss (71 to 90 dB HL)
- Profound hearing loss (greater than 91 dB HL)
What are the Different Types of Hearing Loss?
There are four types of hearing loss:
1. Sensorineural hearing loss: When the problem is in the inner ear, a sensorineural hearing loss is the result. This commonly occurs from damage to the small hair cells, or nerve fibers, in the organ of hearing. Sensorineural hearing loss is the most common type of hearing loss and accounts for more than 90 percent of hearing loss in all hearing aid wearers. The most common causes of this hearing loss are age-related changes and noise exposure. Loss may also result from disturbance of inner ear circulation, increased inner ear fluid pressure, or from disturbances of nerve transmission. There are many excellent options for the patient with sensorineural hearing loss.
2. Conductive hearing loss: When there is a problem in the external or middle ear, a conductive hearing impairment occurs. Conductive hearing loss occurs when sound is not conducted efficiently through the ear canal, eardrum, or tiny bones of the middle ear, resulting in a reduction of the loudness of sound that is heard. Conductive losses may result from earwax blocking the ear canal, fluid in the middle ear, middle ear infection, obstruction of the ear canal, perforation (hole) in the eardrum membrane, or disease of any of the three middle ear bones. All conductive hearing losses should be evaluated by a physician to explore medical and surgical options.
3. Mixed hearing loss - When there are problems in the middle and inner ear, a mixed hearing impairment is the result (i.e. conductive and a sensorineural impairment).
4. Auditory neuropathy spectrum disorder (ANSD): The least common hearing impairment is ANSD. This type of loss requires more in-depth diagnostic testing, including a hearing evaluation with pure tones, otoacoustic emissions (OAEs) and auditory brainstem response (ABR) testing. In this type of hearing loss, the nerve fibers in the organ of hearing typically appear to be functioning well, but a breakdown of the information occurs along the pathway to the brain. A person may still have normal hearing to sounds, but the sound is not encoded properly the brain. This type of hearing disorder is diagnosed more often in children, due in part to newborn hearing screenings that use automated ABR equipment and routine speech screenings by pediatricians and school systems, but can be present in adults as well.
What are the Signs of Hearing loss in Children?
Hearing loss in children can occur from birth to from other acquired factors in life such as ear infections, head trauma, certain medication and genetic factors. You may suspect your child has a hearing loss if you observe any of the following:
- Failed newborn hearing screening
- Delays in speech and language acquisition, including baby babbling
- Frequent ear infections
- Not startling to loud sounds
- Not turning to the location of sounds after six months of age
- Difficulty following verbal directions
- Daydreaming in many situations
- Concerns by school teachers or failed school hearing screening
- Loud volume on the TV or radio
- Complaints from the child that they cannot hear
What Style of Hearing Aid Do I Need?
There are many types of hearing aids today, and the style or device is dependent upon the user's individual needs. There are in-the-ear styles as well as behind-the-ear styles. Also, hearing aid technology has advanced, with many new and improved options from which to choose.
Hearing aids are available in many different sizes and styles, thanks to advancements in digital technology and miniaturization of the internal components. Many of today's hearing aids are considered sleek, compact, and innovative - offering solutions to a wide range of hearing aid users. When selecting a style of hearing aid, the following should be considered:
- The type/degree of the hearing loss
- Power requirements
- Manual dexterity and visual abilities
- Cosmetics and aesthetics
- Skin sensitivities
- Anatomical and medical considerations
What are Assistive Listening Devices (ALDs)?
People with all types and degrees of hearing loss can benefit from an assistive listening device (ALD). Since the microphone of a typical hearing aid is worn on or behind your ear, its ability to enhance the talker-to-background-noise ratio is limited. However, ALDs are designed to increase the loudness of a desired voice, such as a radio, television, or a public speaker, without increasing the background noise. This is because the microphone of the assistive listening device is placed close to the talker or device of interest, while the microphone of the hearing aid is always close to the listener.
ALDs include alarm clocks, TV listening systems, telephone amplifying devices, and auditorium-type assistive listening systems. Many newer devices are small, wireless, and compatible with a person's digital hearing aids. Alarms and other home ALDs may be small devices that are placed discreetly on tables, next to the TV, or on the wall.