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Texas School for the Blind and Visually Impaired Outreach Programs www.tsbvi.edu | 1100 W. 45th St. | Austin, Texas 78756 | 512-454-8631 Hearing Technology and Orientation & Mobility Susie Tiggs, M.Ed. ESC Region XI Hearing Technology and Orientation and Mobility, TETN 11.15.2012 Three Types of Hearing Loss Conductive Loss Due to problems with the ear canal, ear drum, or middle ear and its little bones (the malleus, incus, and stapes) Low frequency loss or equal across frequencies Tend to talk softer than usual or with normal intensity Hear own voices through bone conduction but don’t hear competing noise May hear better in loud, noisy environments because background noise reduce by the conductive problem, and other people speak louder to be heard over the noise Sensorineural Loss Due to problems of the inner ear, also known as nerve-related hearing loss. Audiograms sloping curves Typically more severe at the upper frequencies Increased volume alone doesn’t make up the deficit Generally speak louder to others to be able to hear own voices • Use residual vision to see speaker’s gestures, face, and lips Mixed Loss Combination of conductive and sensorineural hearing loss May be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve Characteristics of both mixed and sensorineural hearing loss Audiograms Intensity or loudness- measured in decibels (dB) Whisper approximately 30 dB Conversations usually 45-50 dB Frequency or pitch-measured in hertz (Hz) Vowel sounds like "u" have low frequencies (250 to 1,000 Hz) Consonants like "s," "h," and "f" have higher frequencies (1,500 to 6,000 Hz) Traffic sounds Quiet residential area – 72 dB Downtown metropolitan area – 84 dB Hearing Technology and Orientation and Mobility, TETN 11.15.2012 Mild Hearing Loss – 26 to 40 dB Loss Understands conversational speech at a distance of 3-?5 feet (face to face) May miss as much as 50% of class discussions if voices are faint or speaker is not in line of vision Difficulty following directions Frequently asks for repetition Conversation outside masked by traffic sounds Moderate Hearing Loss – 41 to 70 dB Loss Conversation must be loud to be understood Will have increased difficulty in group discussions Is likely to misinterpret verbal directions May benefit from hearing aids Conversation outside masked by traffic sounds Severe Hearing Loss – 71 to 90 dB Loss May detect loud voices May be able to identify environmental sounds Need visual cues (speaker's face and especially lips) to understand even part of any conversation Impossible to function in difficult listening situations such as in groups or in noise Profound Hearing Loss – 91+ Loss May detect loud sounds (probably vibrations) Relies on vision rather than hearing Hearing aid may not help much Won’t hear traffic sounds Unilateral Hearing Loss – Loss in one ear May have difficulty hearing faint or distant speech Difficulty localizing sounds Difficulty detecting or understanding soft speech (especially on side with deaf ear) Sound Meter Apps Available for iOS and Android Free or inexpensive Use to determine the loudness of the area you will be working in Hearing Technology and Orientation and Mobility, TETN 11.15.2012 AMPLIFICATION Conventional Hearing Aids CAN: o Make all sounds in the environment louder: speech sounds, the?ventilation system, the TV, the birds chirping? CANNOT: o o o o o "Cure" a hearing loss Create new hair cells Help the child hear sounds at frequencies or pitches at which she has no hearing Make sounds clearer Digital Hearing Aids Computer chip inside Can be individualized to the user’s audiogram Can be programmed to mask background noise Bone Conduction Hearing Aid (BCHA) and Bone Anchored Hearing Aid (BAHA) Bypass the outer and middle ear o Directly stimulate the cochlea Use bone conduction to transmit sound Cochlear Implant Surgically implanted in the cochlea of an ear with a profound hearing loss External parts: o Sound processor with microphone? o Transmitter system? Internal parts: o Receiver – surgically placed under skin o Electrode array – from receiver to cochlea Does not restore normal hearing Helps create a useful representation of sounds in the environment Cochlear Implant Considerations Generally unilateral Hard to localize sound Background noise masks conversation Easy to overestimate safety Hearing Technology and Orientation and Mobility, TETN 11.15.2012 Assistive Listening Devices - (ALD) Microphone/Transmitter – worn by speaker Receiver – attached to hearing aid Microphones Directional microphones o Sounds from front of hearing aids 45 degrees o Tunes out sounds from behind and side – traffic Omnidirectional microphones o Sounds 360 degrees o Conversation lost in background noises Best if two microphones at ear level for localization Gain Increase in loudness May be different at each frequency Allows the hearing aid to compensate for losses at specific frequencies Distorts true traffic noises so hard to judge distance Compression Amplifies softer sounds more than louder sounds Automatically adjusts the amount of gain so that loud sounds won't be distorted or too loud Distorts environmental sounds so hard to judge distance Digital Programming Store more than one listening program in the hearing aid circuit o Choose different microphone or hearing aid settings Remote control or program button on the hearing aid Use different programs for listening in noisy situations or when listening to TV or music Auditory Training Teaching to take full advantage of auditory cues o Developing awareness of sound Gross discrimination of nonverbal stimuli Gross and fine discrimination of speech Auditory training – O&M Include as part of the plan for developing auditory skills for orientation and mobility Hearing Technology and Orientation and Mobility, TETN 11.15.2012 Provide auditory training as part of active travel lessons in natural settings Teach the sound as well as how to use the sound Sound Discrimination o Ability to distinguish between sounds. o Learn these skills by having repeated opportunities to hear everyday environmental sounds and pairing them with their sources Sound localization o Ability to determine where sounds are coming from o Identify distance of sound In Summary Become familiar with the student’s audiogram Learn about the student’s amplification Use sound meter level Include auditory training Team up with the deaf ed teacher Questions? Susie Tiggs, M.Ed. Education Service Center Region XI stiggs @ esc 1 1 .net 8 1 7-74 0 -7 5 8 0 Information, resources, and links from this presentation can be found in a Livebinder at http://bit.ly/PYED0q. Simply click on the tabs and/or subtabs to begin browsing. 0 0 Hearing Technology and Orientation and Mobility, TETN 11.15.2012