Medical Aspects of Hearing Loss

Medical Aspects of Hearing Loss & Latest Trends in Amplification Technology Melanie Lee Macko, Au.D., FAAA, CCC-A Doctor of Audiology Hometown Hearing and Audiology Kansas City Metro Melanie Lee Macko 1996: B.S. Hearing and Speech Sciences--Ohio University 1998: M.A. Audiology--Kent State University 1999: American Speech-Language and Hearing Association Certificate of Clinical Competence in Audiology 2004: Au.D. Doctorate of Audiology--University of Florida 2004: Fellowship with American Academy of Audiology Audiology and Hearing Instrument Specialist Licensure for Missouri and Kansas A locally owned and operated dispensing practice with 21 locations in the Kansas City and St. Louis Metro areas. Overview • • • • • • Reasons to refer to an Audiologist The Audiological Evaluation Types of Hearing Impairment Degrees of Hearing Impairment Auditory Disorders Amplification and Rehabilitation Reasons to Refer to an Audiologist • Client complains of decreased hearing • Client complains of decreased understanding • Verify functional hearing level if client is currently using a hearing aid • Vocational placement relies on adequate hearing acuity The Audiological Evaluation • Non-Medical Otoscopy Normal Tympanic Membrane Abnormal Findings for Otoscopy • Excessive Cerumen • Atresia, Microtia, or Stenosis • Haematomas and Abrasions • Dermatitis, Psoriasis, Shingles, etc. • Tympanosclerosis • Keratosis Obturans • • • • • • Foreign Body Otitis Externa Otitis Media Otomycosis Bony Exostoses Osteomas and Cholesteatomas • Perforations The Audiological Evaluation • Non-Medical Otoscopy • Impedance Typical Impedance Results The Audiological Evaluation • Non-Medical Otoscopy • Impedance and Acoustic Reflex Testing • Speech Reception/Awareness Threshold baseball sunshine mushroom cowboy popcorn hardware sidewalk grandson hotdog airplane railroad iceberg playground birthday drugstore woodwork The Audiological Evaluation • • • • Non-Medical Otoscopy Impedance and Acoustic Reflex Testing Speech Reception/Awareness Threshold Speech Discrimination Testing (quiet-vs-noise) road raise soap third nag jaw tool dog whip door home find jail learn rag lean burn team read far kite doll room moon white back nice yearn loud fall witch turn The Audiological Evaluation • • • • • Non-Medical Otoscopy Impedance and Acoustic Reflex Testing Speech Reception/Awareness Threshold Speech Discrimination Testing (quiet-vs-noise) Pure Tone Thresholds (air and bone conduction) Audiological Terms Conductive: refers to a hearing impairment caused by dysfunction of the outer or middle ear systems Sensorineural: refers to a hearing impairment caused by a dysfunction in the cochlea or VIII cranial nerve Mixed: refers to a hearing impairment which is composed of a conductive component and a sensorineural component Central: refers to a hearing impairment caused by a dysfunction of the neural pathways to the brain Decibel: seen as dB, refers to the loudness level of auditory stimuli Frequency: seen as Hz, refers to the pitch of the auditory stimuli The Audiological Evaluation • • • • • • • • Non-Medical Otoscopy Impedance and Acoustic Reflex Testing Speech Reception/Awareness Threshold Speech Discrimination Testing (quiet-vs-noise) Pure Tone Thresholds (air and bone conduction) Most Comfortable Levels Uncomfortable Levels Speech in Noise Testing Types of Hearing Impairment Normal Hearing Acuity • Thresholds between 0 dB to 20 dB • Normal Middle Ear Function • Excellent Speech Discrimination Abilities – 88% to 100% • Speech Reception Threshold between 0dB to 20 dB • Air Conduction=Bone Conduction in normal range [O O X] [O X] [O X] X] [O [O ] X [O X] Conductive Impairment • Reduced Thresholds • Abnormal Impedance • Abnormal Otoscopy--occasionally • Air-Bone Gaps with bone conduction thresholds within the range of normal • Good Speech Discrimination Scores O [ ] [ ] [ ] X O [ X O ] [O ] X [O X] X O O X Sensorineural Impairment • Reduced Thresholds • Normal Impedance • Air Conduction = Bone Conduction – within 10 dB of each other • Reduced Speech Discrimination Scores O [O X] X ] [O [O X ] X] [O X] [O [O X] Mixed Impairment • • • • Reduced Thresholds Abnormal Impedance Reduced Speech Discrimination Scores Air-Bone Gaps with bone conduction thresholds falling below normal O [ ] [ ] O X O [ ] O X ] [O [O [O X] X X X] Degrees of Hearing Impairment • • • • • • • • Suprathreshold Acuity: -10 dB to -5 dB Normal Acuity: 0 dB to 20 dB Slight Impairment: 25 dB Mild Impairment: 30 dB to 45 dB Moderate Impairment: 50 dB to 60 dB Moderately Severe Impairment: 65 dB Severe Impairment: 70 dB to 90 dB Profound Impairment: 95 dB to 120 dB Configurations of Hearing Impairment Auditory Disorders Ototoxicity • Many medications are known to cause damage to the ear, the auditory system, and the vestibular system. • Anti-inflammatory Drugs, Aminoglycoside Antibiotics, Loop Diuretics, Antimalarials, Chemotherapeutic Agents, Ototopical Medications • Vestibulotoxic: Streptomycin and Gentamycin • Cochleotoxic: Dihydrostreptomycin, Neomycin, Amikacin, and Tobramycin • High Toxicity: Quinine, Streptomycin, and Gentamycin Presbycusis • This is the proper term for hearing impairment caused by the aging process. • There are four major types of presbycusis – Sensory: loss of hair cells, audiogram reveals high-frequency loss with steep drop-off at 2000 Hz – Neural: loss of auditory neurons in the cochlea, loss occurs evenly throughout the cochlear nerve and the cochlea, speech discrimination is disproportionately worse than pure tone audiometry would suggest. – Metabolic: atrophy of stria vascularis--the nutritional support for the cochlea, audiogram reveals flat or slightly sloping configuration with relatively good speech discrimination. – Cochlear Conductive: speculative, believed to be caused by a thickening of the basilar membrane in the cochlea, leads to high frequency impairment Otosclerosis • Vascular spongy bone tissue replaces the normally hard bone and grows around the stapes and oval window in the middle ear space and prevents proper movement • This can cause both conductive and sensorineural hearing impairment, often seen as a slowly progressing conductive hearing impairment • Audiogram often reveals “Carhart’s Notch”, a depression of the bone conduction threshold at 2000 Hz. • Definitive diagnosis is dependent on middle ear exploration. It may be treated surgically by a procedure known as a stapedectomy • It is hereditary in many cases Acoustic Neuroma • A tumor that arises from the neurilemmal sheath of the VIII cranial nerve, typically from the internal auditory canal of the vestibular portion of the nerve • Onset: between 30 to 50 years of age • Onset is primarily gradual • More prevalent in females • Progressive, unilateral sensorineural hearing impairment • Often preceded or accompanied by tinnitus • May be accompanied by dizziness, unsteady gait, headaches, vomiting, speech difficulties, and/or respiratory difficulties Cholesteotoma • A cholesteotoma is a mass of dead epithelial cells from the lateral surface of the tympanic membrane that accumulates within the temporal bone when the tympanic membrane is retracted far enough into the mastoid process. • This mass erodes bone through a process of necrosis and enzymatic activity. This allows for bacterial growth. • This may result in: destruction of the ossicles causing conductive hearing loss, erosion of the labyrinthine capsule causing sensorineural hearing loss and vertigo, erosion into the cranial cavity causing meningitis or brain abscess, infection of the veins in the brain, paralysis of the facial nerve, etc. Otorrhea • Discharge from the ear related to infection • May be caused by otitis externa, chronic otitis media, tympanic membrane perforation, reflux through the eustachian tube, or cholesteatoma Otalgia • Ear Pain • Commonly associated with disorders of the larynx, pharynx, tonsils, jaw pain, bruxism, TMJ, cerumen impaction, ear infection, etc. • Treatment is primarily for the underlying condition Vertigo • Dizziness has many causes, many are unrelated to the ear and the temporal bone. • When it is related to the vestibular system: “rotation” “falling” “spinning” • Other causes: migraines, visual difficulties, diabetes, stroke, hypertension, medications Functional Hearing Disorders • Pseudohypoacusis • Psychological Reasons • Financial Gain: Disability Evaluations, Legal Claims, Benefits Claims • Attention, Special Services and Treatment, Problems with perceived quality of life at home, Behavioral/Psychological Disorders • Test Results inconsistent • Behavior inconsistent Meniere’s Disease • Four symptoms – whirling vertigo that lasts for several minutes to several hours, violent and associated with nausea and vomiting – low-pitched, roaring tinnitus – fluctuating low-tone sensorineural hearing impairment – sense of fullness or pressure in the ear • This disease is caused by a increase in the amount of fluid in the inner ear. • Prevalence: (typical) – – – – 30-60 years of age female (slight) bilateral symptoms positive family history Hyperacusis • • • • • • Oversensitive Hearing Severe loudness discomfort to everyday environmental sounds presented at normal intensities Threshold Hyperacusis: better hearing than age-related sensitivity norms SupraThreshold Hyperacusis: discomfort to sounds less that 65dBSPL with normal hearing sensitivity May become incapacitating Treatment: – – – – – Referral to a treatment program for densensitization therapy Vitamin Therapy Antidepressants, tranquilizers, beta-blockers Biofeedback Counseling Noise Induced Hearing Impairment • Most often occurs in industry and the military • Also occurs from power tools, loud music, racing, hunting, explosions, motorcycles, etc. • Begins as a selective loss at 4000 Hz (noise notch) • As noise exposure continues the notch widens to other high frequencies • Initially seen as threshold shift with tinnitus • Permanent versus Temporary • Occupational noise limits are designed and enforced by OSHA • Best prevention is ear protection and limiting exposure Otitis Media • Cyclical as each stage perpetuates the condition – Eustachian Tube Dysfunction – Bacterial-Laden Secretions – Inflammation – Infection • Treatment with antibiotics and ventilation tube placement. Wax Occlusion • Different consistencies: dry and flaking, hard, soft, sticky, etc. • Complete occlusion can cause up to moderate hearing impairment • Removal via instrumentation, irrigation, or suction • Use of cerumen softening drops • NO Q-TIPS • Interferes with hearing aid use • Interferes with the process of obtaining an earmold impression Tinnitus • Tinnitus is a sound that is heard in either one or both ears. • It is not generated by an external source but rather is produced internally. Current studies are showing that the auditory cortex expects to be stimulated and in the absence of stimulation, generates its own stimuli. • The greater the hearing loss at 4000 Hz the greater the chance of experiencing tinnitus • Millions of people experience tinnitus • May be intermittant or constant, steady or pulsing. • May be caused by: hearing impairment, vascular anomalies, stress, illness, exhaustion, medication, etc. • May be treated with: sound generators/maskers, medication, hypnosis, herbs, habituation therapy, biofeedback, etc. However, the most effective treatment is counseling. Auditory Neuropathy • An auditory nerve disorder in which the auditory signal is not transmitted to the brain properly “wiring problem” • Cause and prevalence not known • Amplification is not beneficial • Symptoms: – – – – – mild to moderate elevation of thresholds present otoacoustic emissions absent acoustic reflexes absent or abnormal auditory brainstem responses speech discrimination abilities worse than expected for degree and configuration of hearing impairment Referrals • • • • • Audiologist Suspected Hearing Loss Tinnitus Hearing Aid Requests Educational Difficulties Monitoring Middle Ear Dysfunction Otorhinolaryngologist • Dizziness/Vertigo • Sudden Hearing Loss • Chronic Ear Infections • Otalgia • Discharge • Suspected Tumor • Middle Ear Fullness Hearing Aids • • • • • • Conventional Hearing Aids Programmable Hearing Aids Trimmer Digital Hearing Aids Digital Hearing Aids Alternative Amplification Assistive Listening Devices Styles of Amplification • • • • • • • • Behind-the-ear Open-Fit over-the-ear Full-Shell in-the-ear Low Profile in-the-ear Half-Shell in-the-ear In-the-canal Mini-Canal Completely-in-thecanal • • • • • • Cros/BiCros Aids Body Aid Bone Conduction Aid Eyeglass Aids Cochlear Implants Bone Conduction Implants • Middle Ear Implants • Brainstem Implants Pictures of Hearing Aids Conventional Hearing Aids • Analog Technology: movements of air converted to electrical current. Original input is slightly compromised (like a photocopy) • Available in all styles • Linear versus Compression • Manual Volume Control • Screwdriver adjusted “trimpots” • Cost: $700 to 1200 each • Few manufacturers continue to offer this technology Programmable Hearing Aids • This technology is now obsolete and is no longer available. Trimmer Digital Hearing Aids • Greater Choice of circuitry options • Digital Sound Quality--Processes sound mathematically, bit by bit. A truer representation of the original sound • Screwdriver adjusted “trimpots” • Lower Cost than Fully Digital Aids • Cost $1000 to 1800 each Digital Hearing Aids • Great Flexibility • Many levels of available features • Multiple Channels, Multiple Bands, Multiple Memories • Noise Suppression • Feedback Management/Cancellation/Interception • Automatic Directional Microphones • Fully Automatic Volume Control and Telecoil • May even switch listening programs based on environmental input • Cost $1300 to $3100 each Digital Features: Convenience • • • • • • • • • • Power On Delay Low Battery Indicator Program Indicator Tones AutoPilot & AutoMic AutoCoil & Automatic Telephone Response Data Logging Experience Manager Smart Voice Self Learning Remote Controls Digital Features: Flexibility • • • • • • Frequency Bands Channels Multiple Memories/Programs Multiple Processing Choices Multiple Earhook Configuration Direct Audio Input/FM compatibility Digital Features: Sound Quality • Automatic Noise Reduction • Voice Priority Processing/Speech Enhancement/Speech Preservation • Expansion • Directional Microphones/Adaptive Directionality • Open Ear Acoustics/Occlusion Manager/EchoBlock • Feedback Management/Cancellation/Phase Inverter/Interceptor • Wind Noise Management Hearing Aid Accessories • • • • • • • • DriAid Kit/Dehumidifier Earmold Air Blower Battery Tester Disinfectant Spray/Wipes Battery Caddy Cleaning Tools Magnets Wax Guards • SuperSeals/Hearing Aid Sweatbands • Eargene • Miracell • Otoease • Otoclips • Wax Guards • JodiVac/Waxman 2000 Surgical Options • Cochlear Implants – Advanced Bionics HiResolution Bionic Ear System – Cochlear Americas Nucleus – Med-El Pulsar CI-100 Bone Conduction Implants: – Cochlear Americas/Entific Medical Systems BAHA (bone anchored HA) Middle Ear Implant: – Med-EL Vibrant Soundbridge Brainstem Implant: – Cochlear Americas Nucleus 24 Auditory Brainstem Implant • • • Assistive Listening Devices • • • • • • • • • • • Amplified Telephones and TTYs Smoke Detectors/Carbon Monoxide Detectors Baby Monitors Alerting Devices (phone ringer & door knocker) Alarm Clocks and Watches Infrared Light Systems Sound field Amplifiers Sound field and Personal FM systems Amplified Stethoscopes Telecoils Closed Captioning Latest Developments in Assistive Listening Devices • • • • MyLink/EasyLink/SmartLink etc. Lexis ELI SoundID Ear Protection • Earplugs – premolded, formable, custom molded, and semi-insert • Earmuffs • Helmets • Electronic Custom Made Earplugs