Demystifying Assistive Listening Devices: The Devil is in the Detail Cheryl D. Davis, Ph.D. Northwest Outreach Center Western Oregon University

Agenda n Benefits n Components n Wireless systems n Troubleshooting n Keys to success Benefits Components Wireless Systems Trouble- shooting Keys to Success

Why use assistive listening devices? n Why aren’t hearing aids enough? n What do hearing aids do? –s ou nd s > sounds n What do ALDs do? –sounds > sounds n ADA mandates effective communication

Components n Individual n Sound n Environment n Sound Source n Microphones n Transmitter and Receiver Systems n Coupling Devices n Telecoils

Components: Individual n Hearing loss –binaural or monaural –severity (dB) and frequency (Hz) –conductive or sensorineural –may fluctuate or be progressive n Age at onset of loss n Acceptance of loss n Speech reading ability n Hearing aid/T-coil use n Knowledge of and comfort with ALDs

Components: Sound n Dimensions –Frequency –Loudness n Impact on Speech Intelligibility –Distance –Signal-to-Noise Ratio –Reverberation

Components: Environment n Light or dark n Uncovered windows n Distance from speaker n Room acoustics and noise

Components: Sound Source n Instructor giving a lecture n Panel of speakers n Video or audio recording n Q&A from the audience n Hard of hearing student n Neighboring student

Communication Tips n Face-to-face communication n Maximal lighting conditions n Don’t yell n Be patient n Don’t be afraid to write

Components: Microphones n Omnidirectional n Unidirectional n Lavaliere or Lapel n Table top or conference n Placement is vital! –Remember effect of distance on sound

Components: Transmitter and Receiver Systems n FM n Infrared n Electromagnetic induction loop n Hardwired systems

Components: Coupling Devices n No hearing aid OR no T-coil –headphones –earbuds n Hearing aid with T-coil –neckloop –silhouette –headphones n Other methods –Direct Audio Input –FM Boot –Cochlear implants

Components: Telecoils n Hearing Aids: Microphone vs T-coil n Not all hearing aids have T-coils n T-coils are not as sensitive as hearing aids n Proximity is important n Commonly found in telephones and speakers n Susceptible to electromagnetic interference

T-coils & Couplers & Mics! Oh My! n Encourage T-coil purchase and usage. n Inform students about the possibility of a Mic/T/Both switch. n Make environmental mics available. n Experiment with different coupling devices.

FM n Uses radio waves n Transmitter –a radio station n Receiver –a radio n Crib Monitor

True or False? n You can leave the room and still hear the presentation. n This system can be used indoors or outdoors. n You must have a receiver to use this system. n You must have a hearing aid to use this system. n You can use FM in multiple rooms in a building. n I can use my FM receiver with your FM transmitter.

FM Advantages n Very portable n Very easy to set up and use n Offers great flexibility of movement n Used indoors or outdoors n Appropriate for mild to profound losses n Receiver can be covered or put in pocket n No fluctuation in strength of signal

FM Disadvantages n Receivers are required for everyone n Receivers vary in quality and durability n Potential for outside interference –72-76 MHz bandwidth allotted by FCC –police band, construction walkie talkies, pagers n Receivers and transmitters must be on the same channel n There must be 1 free channel between systems used in close proximity

Infrared n Uses infrared light n Transmitter-emitter panel –like the infrared diode on a remote control –emits signal in 60 degree cone-like a flashlight n Receiver –like the infrared receiver area on a TV or VCR n TV headphones

True or False? n You can leave the room and still hear the presentation. n This system can be used indoors or outdoors. n You must have a receiver to use this system. n You must have a hearing aid to use this system. n You can use infrared in multiple rooms in a building. n I can use my IR receiver with your IR transmitter.

Infrared Advantages n Compatibility: 95 kKz is industry standard –Home receivers can be used with public transmitters –250 kHz if high intensity lighting n No spillover means security n Can be used in adjacent rooms n Widest bandwidth and best sound reproduction n Appropriate for mild to moderate/severe loss n Not affected by radio transmission

Infrared Disadvantages n Receivers required for everyone n Must have direct line of sight n Can’t cover the receiver or put in pocket n Indoor or evening use only n High intensity or fluorescent lights cause interference n Large areas require multiple emitter panels n Quality varies with company

Electromagnetic Induction Loop n Uses electromagnetic fields of energy –Power lines n Transmitter-Loop of several wires n Receiver –T-coil in hearing aid –desktop receiver n Telephone and other speakers n As small as a neck loop or as large as an auditorium

True or False? n You can leave the room and still hear the presentation. n This system can be used indoors or outdoors. n You must have a receiver to use this system. n You must have a hearing aid to use this system. n You can use induction loops in multiple rooms in a building. n I can use my loop receiver with your loop transmitter.

Induction Loop Advantages n Low equipment costs after installation n Easy operation n Lasts forever n Induction receivers are compatible with ALL loop systems n Unobtrusive with T-coil hearing aid T

Induction Loop Disadvantages n Installation costs may be high n Installation may not be possible in historic buildings n Can’t assume everyone will have a T-coil n Susceptible to electrical interference and spill over n Must sit around looped area n May be dead areas within loop

Troubleshooting: General n Batteries charged? n Deductive reasoning –T-coil working? try it out with a phone call –try different couplers n Ultrasonic sensors n Check with local SHHH group n Cultivate an expert n Call the company!

Troubleshooting: FM n Are the receiver & transmitter on the same station? –Color code or number them n What sources of interference are close by? –Station drift-your system OR someone else’s –police band, construction walkie talkies, pagers n Must have one free channel difference if 2 different stations are being used in rooms next to each other.

Troubleshooting: Infrared n Is the room bright, or is direct sunlight present? n Is anything blocking the line of sight? n Are high intensity fluorescent lights present?

Troubleshooting: Induction Loop n Are there sources of electrical interference and spillover nearby? n Portable systems can be a mobility hazard. Are wires protected?

Keys to Success for the Speaker n Avoid drawing attention to the individual user n Repeat questions from the audience n Place mic close to mouth (or other sound source)but NOT in front of the mouth n Use an unidirectional mic when possible n Turn off or step away from overhead when not in use n Do not direct their attention away from your face, and then start talking!

Keys to Success for the Speaker n Repeat questions from the audience n Rephrase instead of repeat n Don’t stand in front of windows or bright lights n Face your audience when speaking n Avoid talking while the class is retrieving materials

Keys to Success for the Student n Batteries charged and T-coil working n Proximity to T-coil n Proximity to interference –just changing seats may help n Continue to sit within 20 ft. of the speaker if you will use speech reading n Interact with others about coping techniques-SHHH, Beyond-Hearing

Keys to Success for the Student n Make sure the volume is down when you first put the coupler on n Experiment with different couplers, locations, and environments n Get an environmental mic or hearing aid with mic/t/both position n Check out equipment ahead of time n While you are at it, check out the instructors too! n Be specific

Keys to Success for the Service Provider n Cultivate an expert for troubleshooting n Always check out the system ahead of time n Experiment n Encourage users to experiment n Show how ALDs can be unobtrusive n Advertise that the systems are available n If the user isn’t ready yet –SHHH or ALDA meetings or web sites – lists like Beyond-Hearing –provide a fact sheet on the devices available from your program –provide info about impact of distance, room noise on understanding

Review n Consider the individual first. n Evaluate the requirements of the setting and the properties of the equipment. n Buy equipment from companies that will help you troubleshoot. n Don’t forget the non-electronic communication tips!

Cheryl D. Davis, Ph.D., Coordinator Northwest Outreach Center Regional Resource Center on Deafness Western Oregon University Monmouth OR (v/tty) (fax) Contact Information