Presentation on theme: "The Issue for VR 28 million people in US have a hearing loss (10%)"— Presentation transcript:
1 Basic Audiology: Understanding the Xs and Os Developed by: Sheila Hitchen Tweaked by: Cheryl Davis
2 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 earsHearing women stay in labor force 9 years longer than hard of hearing women17% more hard of hearing female workers aged exit the labor forcePeople leave jobs because of:Inability to continue to carry out dutiesSocial difficulties and isolationData from U.S. Census Bureau & the Center for Bilingual Education and Research, Arizona State University.
3 Who Would You Hire or Promote? Worker #1DepressedDefensive/ParanoidPoor self imagePoor social skillsPoor listening skillsFeels like they have no controlWorker #2Not depressedLess defensive/ paranoidNormal self imageNormal social skillsNormal listening skillsFeels like they are in control
4 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?
5 You want me to what??? Definitely understood Fairly certain he understoodCertain he did not understandCertain he understood (but didn’t)Doesn’t know he didn’t hearIndividuals 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.
6 “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.
7 Individual Experience Includes: Hearing lossbinaural or monauralvaries in severity (dB) and frequency (Hz)may fluctuate or be progressiveAge at onset of lossAcceptance/coping strategiesSupport structureHearing aid/T-coil use/AT useIdentityDeaf Hard of HearingLate Deafened Cochlear Implant UserThe 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.
9 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.
10 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.
11 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 FrequencyHigh Frequency
12 Normal Hearing Looks Like: Normal Inner&OuterHair Cells
14 Causes: Congenital Illness and Infection Ototoxic Medication Maternal RubellaGenetic SyndromesUsher SyndromeWaardenburg SyndromeIllness and InfectionMeasles, MeningitisOtitis MediaOtotoxic MedicationNoise Exposure
15 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
16 Causes: Presbycusis (Age Related) Progressive sensorineural lossHigh frequencies first55 to 65: high frequencies in the speech range begin to be affectedOther considerations:Macular DegenerationManual Dexterity Issues
17 Other Issues: Tinnitus Characterized by ringing, rushing, buzzing sounds in earsDue to damage to cochlear hair cellsDiet and stress management may help control symptomsIncurableSome use maskers toblock ringing
18 Other Issues: Meniere’s Disease Fluctuating:Hearing lossRotational vertigoTinnitusSense of Aural FullnessBalanceVisualTactileVestibular system
20 Components of a Hearing Test SpeechAudiometryAir & BoneConductionLegendComments
21 The Audiogram Frequency is measured in hertz (Hz) BassTrebleFrequency is measured in hertz (Hz)Common range shown is 250 Hz to 8000 HzLow numbers = low tonesHigh numbers = high tones
22 The Audiogram Volume is measured in decibels (dB) The higher the line, the better the client’s hearing90 dB loss does not indicate the person is 90% Deaf!
23 The Audiogram X =left O =right ear Normal: 0-20 dB Mild: 20-40 dB Moderate: dBSevere: dBProfound: 90+ dBALL levels have vocational impacts!
24 Air ConductionTests the ability of sound to be processed by the hearing mechanism.Shows severity and frequency of the individual’s loss.
25 Bone ConductionTests the ability of the middle ear to conduct sound to the inner ear.Used to determine the type of loss.
26 TympanometryTests the function of ear drum and air pressure in middle earA diagnostic tool for middle ear problems.
27 Speech Audiometry How well does person hear speech? Speech Reception ThresholdSpeech Detection ThresholdDiscrimination ScoreMost Comfortable LevelUncomfortable LevelSee “What is a Hearing Aid Evaluation” on WROCC website
29 Hearing Aids Simplified Microphone—picks up soundAmplifier—makes sound louderSpeaker—sends sound down ear canalBigger = more space for battery!ITEBTEITCCIC
30 Common Styles Behind the Ear (BTE) In the Ear (ITE) In the Canal (ITC) Completely in the Canal (CIC)Body AidsCROSContralateral Routing of Signal
31 Circuit Technology (Analog vs. Digital) Least ExpensiveConventionalNon-programmable linear (analog)ProgrammableAnalog (with screwdriver)Digital (with computer)Digital Signal ProcessingMost Expensive
32 Hearing Aid Terminology Programmable means how you set all the options or ‘tune’ the hearing aidProgram 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
33 Hearing in Noise Signal to noise ration problem Noise Noise NoiseHearing in NoiseSignal to noise ration problemDirectional MicrophonesNoise reductionAssistive Listening DevicesTelecoilsNot as sensitive as hearing aidsSusceptible to electromagnetic interferenceDirect Audio InputFM BootLet’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.
34 Two Hearing Aids Vs. One Better hearing in noise Head Shadow Effect Improved localizationDeterioration of unaided earImproved understanding of speechSave battery powerLess tiringBetter balance of soundHelp mask tinnitusREMEMBER—Unemployment rates are about the same with a loss in one or both ears!DifferentiatedRight ear: cells respond more to speechLeft ear: cells respond more to music
36 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.
37 What About Cochlear Implants? Auditory ProsthesisSurgical procedureMedical clearance requiredReplaces hearing aidCan restore independence for late-deafened people**Destroys existing Cochlear cellsDoes not restore normal hearingTechnology constantly improvingDoes not change the individual’s identity
38 How do You Define Success? Environmental soundsImproved speech reading abilitySpeech of familiar othersSpeech of strangersAble to enjoy musicAble to use phonePersonal storiesBB & WHKSSRMT
39 Cochlear Implants 1970s: CIs will never work 1980s: CI users will never understand speech1990s: They will never appreciate music2000s: They will never hear like normal-hearing people doNext: Bilateral implantation?Note: about 45,000 people have CIs to date.
40 Resources SHHH-Self Help for Hard of Hearing People (many materials available)ALDA-Association of Late Deafened AdultsCIAI-Cochlear Implant Association InternationalNAD-National Association of the DeafWROCC Outreach Site at WOUand click on Training MaterialsHearing Aid PrimerWhat is a Hearing Aid Evaluation?How to Read an Audiogram
41 Resources “Sound and Fury”, video by Josh Aronson, 2000 Wired for Sound, by Bev BidermanCochlear Implant Forum Listserv –To:From: (Your address)Subject: (Leave it blank)Message: Subscribe ci (your name)Cochlear Corporation –Advanced Bionics (Clarion) –www.advancedbionics.comMed-El –Consumers Guide to Hearing Aidsevaluation of consumer’s environmentSurvivor’s Manual: