Presentation on theme: "Basic Audiology: Understanding the Xs and Os Developed by: Sheila Hitchen Tweaked by: Cheryl Davis."— Presentation transcript:
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 Whats the big deal? You hear pretty good. You speech read, right? Your hearing aids fix it. You can hear if you want to. You dont need accommodations… –Your speech is clear, so you hear well, –You heard me fine in my office, –You talked to me on the phone.
You want me to what??? Definitely understood Fairly certain he understood Certain he did not understand Certain he understood (but didnt) Doesnt know he didnt hear
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
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 doesnt help!) May be due to hair cell/nerve damage. May be due to problem with auditory nerve.
High frequency cells take the brunt of the day-to-day damage; most people lose high frequency hearing first. People hear the sounds, but cant make out the words: "Speak up and quit mumbling!!" Low Frequency speech sounds are fewer than high frequency. People have difficulty hearing words in two competing signals (cocktail party effect) Cochlear Structure
Normal Hearing Looks Like: Normal Inner & Outer Hair Cells
Data courtesy of the National Institute of Occupational Health and Safety At present exposure limits, one in four people will develop a permanent hearing loss as a result of their occupational exposure to noise hazards.
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: Menieres 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
The Audiogram Frequency is measured in hertz (Hz) Common range shown is 250 Hz to 8000 Hz Low numbers = low tones High numbers = high tones BassTreble
The Audiogram Volume is measured in decibels (dB) The higher the line, the better the clients 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 individuals 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
Hearing Aids Simplified Microphonepicks up sound Amplifiermakes sound louder Speakersends sound down ear canal Bigger = more space for battery!
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 Directional Microphones Noise reduction Assistive Listening Devices Telecoils –Not as sensitive as hearing aids –Susceptible to electromagnetic interference Direct Audio Input FM Boot
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
T The electrodes then stimulate the auditory nerve which sends the signals to the brain. The brain interprets these electrical signals into sounds. Cochlear implants are designed to by-pass the non-functioning cochlear hair cells and provide direct stimulation to the auditory nerve. The microphone sends sounds to the processor, which codes the sounds into useful speech, music, etc. Sounds are transmitted through the skin to the receiver/stimulator via the magnetic headset. The codes are then converted to electrical signals which activate the coiled electrode arrays in the cochlea. Some sounds are easier for the brain to figure out than others. Environmental sounds are less complex that combinations of speech sounds.
What About Cochlear Implants? **Destroys existing Cochlear cells Does not restore normal hearing Technology constantly improving Does not change the individuals identity Auditory Prosthesis Surgical procedure Medical clearance required Replaces hearing aid Can restore independence for late- deafened people
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: email@example.com –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 consumers environment Survivors Manual: http://shhhor.org/survivor_manual.pdf