Basic Audiology: Understanding the Xs and Os Developed by: Sheila Hitchen Tweaked by: Cheryl Davis

The Issue for VR 28 million people in US have a hearing loss (10%) HOH population unemployed due to disability: 22.5% The rate is essentially constant regardless of whether the loss is in one or both ears Hearing women stay in labor force 9 years longer than hard of hearing women 17% more hard of hearing female workers aged 45-54 exit the labor force People leave jobs because of: Inability to continue to carry out duties Social difficulties and isolation Data from U.S. Census Bureau & the Center for Bilingual Education and Research, Arizona State University.

Who Would You Hire or Promote? Worker #1 Depressed Defensive/Paranoid Poor self image Poor social skills Poor listening skills Feels like they have no control Worker #2 Not depressed Less defensive/ paranoid Normal self image Normal social skills Normal listening skills Feels like they are in control

Myths & Misunderstandings “What’s the big deal? You hear ‘pretty good.’” “You speech read, right?” “Your hearing aids ‘fix’ it.” “You can hear if you want to.” “You don’t need accommodations… Your speech is clear, so you hear well, You heard me fine in my office, You talked to me on the phone.” Service providers are often confused when presented with an individual who is hard of hearing. How much of a hearing loss does one need to have in order to justify providing an accommodation? The decision-making process seems to be much easier if presented with a culturally Deaf individual who uses sign language for communication. Obviously, an interpreter is required to facilitate most interactions between signing and non-signing individuals. Individuals who are hard of hearing, though, may seem to hear well in some situations and not in others. In fact, hearing loss is so common that most of us have some experience interacting with someone who has a loss. We may have heard someone say (or even said ourselves) ‘You can hear when you want to’ or assumed that speechreading solves all communication problems. We assume that unless the loss is severe or profound, the individual can hear ‘pretty good’. A partial hearing loss is especially confounding because the individual may be able to communicate well with some people and not others, hear in some situations, communicate exceptionally in the intake interview, or even talk on the phone. How does one justify providing services to someone who seems to do so well on his or her own?

You want me to what??? Definitely understood Fairly certain he understood Certain he did not understand Certain he understood (but didn’t) Doesn’t know he didn’t hear Individuals with hearing loss are using residual hearing, amplification, and speech reading to decode the spoken message. Speech reading is a skill that many hard-of-hearing individuals develop, sometimes without realizing it. Individuals will say, ‘If I can’t see you, I can’t hear you.’ Nonetheless, only 33% of English speech sounds are visible on the mouth. Thus, speech reading involves using residual hearing, watching body language and facial expressions, English language skill, continuous visual access to the face, and knowledge of the topic to correctly fill in the blanks. While it is a skill that can be improved to some extent with training, not everyone will be able to speech read in the language-dense postsecondary setting. Even a skilled speech reader will not be able to follow group discussions or instruction that is given while the instructor is looking down or has her back to the class writing on the board because continuous visual access to the face is required. While we may assume that an individual either did or did not understand something we said, there are actually many levels of understanding involved. An individual may understand with confidence 100% of what you said. Alternatively, he may have understood what you said with a fair amount of confidence. This individual may seek clarification in this situation. There is also the situation where the individual knows something was said, but did not understand. He may ask for a repeat, or try and figure it out from other things that are said. On the other hand, the individual may believe that he heard you correctly but did not, and does not realize that he didn’t. This is the joke where one person asks ‘Nice watch. What kind is it?’ and the other replies ‘5:20.’ Finally, there is the situation where the individual doesn’t hear, and doesn’t know that something was said. A common example of this is when students are packing their books to leave class and the teacher announces a room change for the next class. Between looking down to pack books together and room noise, the hard of hearing student will not know the announcement has been made.

“I have an 80% hearing loss.” There is a much greater range of sound frequencies that what is shown in the above graphic. However, for educational purposes, we deal with the speech frequencies.

Individual Experience Includes: Hearing loss binaural or monaural varies in severity (dB) and frequency (Hz) may fluctuate or be progressive Age at onset of loss Acceptance/coping strategies Support structure Hearing aid/T-coil use/AT use Identity Deaf Hard of Hearing Late Deafened Cochlear Implant User The first component is the individual with a hearing loss. There is nothing straightforward about hearing loss or how people react to it. This creates a great deal of confusion for people who have little or no experience with hearing loss, and often results in beliefs and attitudes about the individual with a hearing loss that are ill founded. They do not understand why the individual might hear one person better than another, how they can use a telephone, or why they seem to hear fine in some situations or not others. The individual may have a loss in one or both ears. That loss may be different in each ear. Hearing may continue to deteriorate or fluctuate with allergies or illness. The individual may be able to hear high sounds but not low, or vice versa. They may have difficulty interpreting what they are hearing. The person may or may not use hearing aids, or may use aids for one or both ears. They may have been dealing with the loss since childhood, or only recently. And like the rest of us, they will have varying levels of tolerance for frustration, stress and ambiguity-all of which are a part of trying to communicate with people who do not understand the nature of hearing loss. Some have developed effective coping strategies, some have not. Their families, coworkers, and bosses, likewise, provide varying degrees of support. Speech reading does not come naturally-it is a trained skill. Even so, only 30-35% of the English language is visible on the lips. Accents and mustaches wreak havoc with the best speech reader. People must rely on contextual cues and what they CAN hear to be effective speech readers. Finally, hearing loss does not come with an instruction manual. Assistive technology is wonderful--if you are aware of it and know how to use it. You should not expect that the person with a hearing loss will be an expert in the hearing mechanism, the psychology of grieving their loss, or assistive listening devices.

How Hearing Works

Conductive Hearing Loss Sound does not move into inner ear efficiently. Due to a problem in either outer or middle ear. May be medically or surgically treated or cured. Inner ear works fine. Amplification may help to get sound through the auditory system.

Sensorineural Hearing Loss Sound is not interpreted efficiently by inner ear. (Louder doesn’t help!) May be due to hair cell/nerve damage. May be due to problem with auditory nerve.

Cochlear Structure Low Frequency High Frequency Low Frequency speech sounds are fewer than high frequency. People have difficulty hearing words in two competing signals (cocktail party effect) High frequency cells take the brunt of the day-to-day damage; most people lose high frequency hearing first. People hear the sounds, but can’t make out the words: "Speak up and quit mumbling!!" Low Frequency High Frequency

Normal Hearing Looks Like: Normal Inner & Outer Hair Cells

Sensorineural Hearing Loss Going… Going… GONE

Causes: Congenital Illness and Infection Ototoxic Medication Maternal Rubella Genetic Syndromes Usher Syndrome Waardenburg Syndrome Illness and Infection Measles, Meningitis Otitis Media Ototoxic Medication Noise Exposure

At present exposure limits, one in four people will develop a permanent hearing loss as a result of their occupational exposure to noise hazards. Data courtesy of the National Institute of Occupational Health and Safety

Causes: Presbycusis (Age Related) Progressive sensorineural loss High frequencies first 55 to 65: high frequencies in the speech range begin to be affected Other considerations: Macular Degeneration Manual Dexterity Issues

Other Issues: Tinnitus Characterized by ringing, rushing, buzzing sounds in ears Due to damage to cochlear hair cells Diet and stress management may help control symptoms Incurable Some use maskers to block ringing www.ata.org

Other Issues: Meniere’s Disease Fluctuating: Hearing loss Rotational vertigo Tinnitus Sense of Aural Fullness Balance Visual Tactile Vestibular system http://www.menieresinfo.com http://www.menieres.org http://www.vestibular.org

Reading the Audiogram

Components of a Hearing Test Speech Audiometry Air & Bone Conduction Legend Comments

The Audiogram Frequency is measured in hertz (Hz) Bass Treble Frequency is measured in hertz (Hz) Common range shown is 250 Hz to 8000 Hz Low numbers = low tones High numbers = high tones

The Audiogram Volume is measured in decibels (dB) The higher the line, the better the client’s hearing 90 dB loss does not indicate the person is 90% Deaf!

The Audiogram X =left O =right ear Normal: 0-20 dB Mild: 20-40 dB Moderate: 40-70 dB Severe: 70-90 dB Profound: 90+ dB ALL levels have vocational impacts!

Air Conduction Tests the ability of sound to be processed by the hearing mechanism. Shows severity and frequency of the individual’s loss.

Bone Conduction Tests the ability of the middle ear to conduct sound to the inner ear. Used to determine the type of loss.

Tympanometry Tests the function of ear drum and air pressure in middle ear A diagnostic tool for middle ear problems.

Speech Audiometry How well does person hear speech? Speech Reception Threshold Speech Detection Threshold Discrimination Score Most Comfortable Level Uncomfortable Level See “What is a Hearing Aid Evaluation” on WROCC website

Options for Amplification

Hearing Aids Simplified Microphone—picks up sound Amplifier—makes sound louder Speaker—sends sound down ear canal Bigger = more space for battery! ITE BTE ITC CIC

Common Styles Behind the Ear (BTE) In the Ear (ITE) In the Canal (ITC) Completely in the Canal (CIC) Body Aids CROS Contralateral Routing of Signal

Circuit Technology (Analog vs. Digital) Least Expensive Conventional Non-programmable linear (analog) Programmable Analog (with screwdriver) Digital (with computer) Digital Signal Processing Most Expensive

Hearing Aid Terminology Programmable means how you set all the options or ‘tune’ the hearing aid Program means different settings for different listening situations (e.g., music, using the phone/telecoil, in noisy situations) Channel means how many different ranges of frequencies are amplified

Hearing in Noise Signal to noise ration problem Noise Noise Noise Hearing in Noise Signal to noise ration problem Directional Microphones Noise reduction Assistive Listening Devices Telecoils Not as sensitive as hearing aids Susceptible to electromagnetic interference Direct Audio Input FM Boot Let’s look a little more closely at T-coils. Advocates will tell you that one of the most important things to get in a hearing aid is a good telecoil. What constitutes a good T-coil? Well, they are not as sensitive as hearing aids and require that the volume be turned up. Better T-coils have a higher sensitivity. Some may lose as much as 25dB, others only 3dB. The smaller the number the better. They should also be vertically oriented, as in the lower diagram, because they pick up the signals better in this position. So just what is it? Delving into electronics a little, the alternating current of an audio signal creates an electromagnetic field that radiates away from the wire. When two wires are close, the electromagnetic field of one will induce a current in the other wire. The T-coil in a hearing aid is actually a small electromagnetic induction coil, i.e., a wire. NOTE: no matter what type of ALD is being used, the coupling device is receiving an audio signal that creates an electromagnetic field. The coupling device may convert the signal to sound, as in the case of headphones, or, as with neckloops and silhouettes, it may simply provide a way of getting the wire of the coupler close to the wire (the T-coil) in the hearing aid so that this induction can occur, and then the hearing aid will convert the electromagnetic field to sound. The hearing aid microphone ONLY picks up acoustic sound waves. The T-coil ONLY picks up electromagnetic signals. The most common use of the T-coil is with the telephone, and it provides a vivid illustration of the difference between the mic and the T-coil functions on a hearing aid. Telephone speakers (as well as other speakers) contain induction coils. If an individual is using the telephone with the hearing aid on mic, he or she would put the telephone over the ear to hear. If, on the other hand, the individual is using the T-coil, he or she would place the earpiece of the phone over the hearing aid to bring the two wires to the closest proximity. If the individual is wearing a body-type aid, the earpiece of the phone may not be placed anywhere near the ear. The same applies to headphones, which also have electromagnetic fields (although some are stronger than others). Without T-coils, the headphones would be placed over the ears; with T-coils, the headphones would be placed over the hearing aids. T-coils are susceptible to electromagnetic interference produced by microwaves, lights, computer monitors, appliances, power lines, elevator cables--anything that produces electromagnetic fields. If problems are occurring, watch for hidden sources of interference.

Two Hearing Aids Vs. One Better hearing in noise Head Shadow Effect Improved localization Deterioration of unaided ear Improved understanding of speech Save battery power Less tiring Better balance of sound Help mask tinnitus REMEMBER—Unemployment rates are about the same with a loss in one or both ears! Differentiated Right ear: cells respond more to speech Left ear: cells respond more to music

What About Cochlear Implants?

T The microphone sends sounds to the processor, which codes the sounds into useful speech, music, etc. Cochlear implants are designed to by-pass the non-functioning cochlear hair cells and provide direct stimulation to the auditory nerve. Some sounds are easier for the brain to figure out than others. Environmental sounds are less complex that combinations of speech sounds. Sounds are transmitted through the skin to the receiver/stimulator via the magnetic headset. The electrodes then stimulate the auditory nerve which sends the signals to the brain. The brain interprets these electrical signals into sounds. The codes are then converted to electrical signals which activate the coiled electrode arrays in the cochlea.

What About Cochlear Implants? Auditory Prosthesis Surgical procedure Medical clearance required Replaces hearing aid Can restore independence for late-deafened people **Destroys existing Cochlear cells Does not restore normal hearing Technology constantly improving Does not change the individual’s identity

How do You Define Success? Environmental sounds Improved speech reading ability Speech of familiar others Speech of strangers Able to enjoy music Able to use phone Personal stories BB & WH KS SR MT

Cochlear Implants 1970s: CIs will never work 1980s: CI users will never understand speech 1990s: They will never appreciate music 2000s: They will never hear like normal-hearing people do Next: Bilateral implantation? Note: about 45,000 people have CIs to date.

Resources SHHH-Self Help for Hard of Hearing People www.shhh.org (many materials available) ALDA-Association of Late Deafened Adults www.alda.org CIAI-Cochlear Implant Association International www.cici.org NAD-National Association of the Deaf www.nad.org WROCC Outreach Site at WOU www.wou.edu/nwoc/leavitt.htm www.wou.edu/wrocc and click on Training Materials Hearing Aid Primer What is a Hearing Aid Evaluation? How to Read an Audiogram

Resources “Sound and Fury”, video by Josh Aronson, 2000 Wired for Sound, by Bev Biderman Cochlear Implant Forum Listserv – Email: To: listser@yorku.ca From: (Your e-mail address) Subject: (Leave it blank) Message: Subscribe ci (your name) Cochlear Corporation – www.cochlear.com Advanced Bionics (Clarion) –www.advancedbionics.com Med-El – www.med-el.com www.hearinglosshelp.com/twohearingaids.htm www.hearinghealth.org Consumers Guide to Hearing Aids www.beyondhearingaids.com: evaluation of consumer’s environment Survivor’s Manual: http://shhhor.org/survivor_manual.pdf