Aural Rehab - Lecture 10
ALDs: Induction Loop Systems - where are they popular?
Popular in classrooms, churches, auditoriums, theater before the advent of FM systems, currently a resurgence in popularity
ALDs: FM Systems - how is coupling done? (4)
▪ A microphone is placed close to the sound source ▪ The FM transmitter of the system uses the electrical signal from the microphone to modulate a designated carrier frequency ▪ The FM signal is broadcast over a broad area—usually several hundred feet ▪ The listener uses an FM receiver to pick up and demodulate the signal, and then delivered to the listener's ear via headsets or through a HA (direct audio input) **************************************************** ▪ coupling device is done through DAI
ALDs: Hardwired Systems - what can a personal amplification system be a good alternative for? (2)
▪ A Personal Amplification System can be a good alternative for people who are bedridden or physically or mentally unable to operate a conventional hearing aid ▪ Also useful for professionals who interact with HI individuals who may not own a HA
ALDs: Induction Loop Systems - induction loop systems for personal use
▪ Individuals can also purchase induction loop systems for personal use ▪ The most typical application is for TV viewing - The mic of the systems is placed near the TV (or the signal can be obtained from an output jack) - The electrical signal from the mic is sent through a coiled wire that is looped around a viewing area - The listener sits anywhere in the looped area and can pick up the signal using the HA telecoil
ALDs: Hardwired Systems - weaknesses (3)
▪ Must have a direct electrical connection between the sound source and the listener (confined movement) ▪ Often poor S/N, depending on how it's used ▪ it picks up everything , it doesn't have a mic that separates speech from noise ***************************************************** ▪ SNR is NOT why you get these
ALDs: Infrared Systems - receiver (3)
▪ The receiver for the system is typically a battery-powered headset—it uses a photodiode to pick up the infrared signal, which is demodulated and heard via headset (or via coupling to a HA) ▪ DAI of BTE ▪ Neckloop ******************************************* ▪ DAI makes a direct connection with a hearing aid, either with a boot or a neckloop - the neckloop is for people that don't have hearing aids
The Use of ALDs in the School System - how do FM soundfield systems work? (5)
▪ The teacher wears a wireless mic that sends the signal to an AC-powered FM transmitter ▪ The FM transmitter sends an FM signal throughout the room ▪ FM receivers (attached to soundfield speakers) are located strategically around the room ▪ The soundfield speakers broadcast the teacher's voice throughout the room - Individual desk-top speakers are also available for students with special needs ****************************************************************** ▪ soundfield systems do have to have a professional installation but doesn't have to be perfect the way an induction has to be ▪ for personal systems there's no installation, the kid and the teacher just has to wear their parts ▪ kids in middle school or high school can have different microphones with different carrier frequencies for teachers in different rooms ▪ because the signal can travel through walls, kid needs to verify with the teacher that they're on the right frequency because they could be sitting in science class but listening to math
ALDs - two broad categories
▪ Two broad categories: hardwired and wireless ▪ Hardwired systems require a direct electrical connection (a wire) between the microphone of the system (at the signal of interest) and the receiver of the system (at the ear of the listener) ▪ Wireless technologies transmit the signal from the microphone to the receiver without a direct electrical connection ▪ Induction loop ▪ Infrared ▪ FM
ALDs - what are they used for? (5)
▪ Used to help HI listeners understand speech when listening conditions are less than ideal - When the SNR is poor because of background noise - When the person is listening from a distance - When reverberation is present ▪ ALDs can be used in conjunction with a hearing aid or can be used in place of a hearing aid **************************** ▪ SNR in a lot of situations isn't favorable - when a person's listening from a distance, when there's reverberation, etc.
ALDs: Induction Loop Systems - consists of... (3)
▪ A typical induction loop system consists of a microphone which is placed close to the sound source ▪ The electrical signal from the microphone is boosted by an amplifier and sent through a coil of wire placed around the floor (or ceiling) of a room, producing an electromagnetic signal in the area that is looped ▪ Listeners with a hearing aid equipped with a telecoil can simply activate the telecoil in their HA ************************************************************************* ▪ when they go into that area that's looped, they can go into that space and pick up a signal from that microphone via their telecoil
Alerting Devices
▪ Alerting Devices are used to alert people with hearing loss to sounds that they might otherwise miss ▪ Although these devices are used primarily by individuals who are deaf, others with mild to moderate hearing loss can make use of them as well—if they are have particular difficulties ******************************************** ▪ primarily people who are deaf use these devices ▪ we can also recommend these to people who are moderate hearing loss but really deep sleepers
Alerting Devices - how can they be purchased?
▪ Alerting Devices can be purchased as individual units, each devoted to alerting a person to one particular sound—or, there are a number of "universal" systems that monitor a variety of systems around the house ▪ Often, the degree of HL will dictate which type of system to buy—the more HL the more likely the need for a universal system ▪ Used for: Alarm clock, telephone, doorbell, smoke detector, etc.
ALDs - alerting devices (2)
▪ Alerting devices are used to alert individuals to acoustic stimuli they might otherwise miss ie: alarm clock, smoke detector, crying baby, or a ringing telephone ▪ Most commonly used by individuals with a severe to profound hearing loss *********************** - this doesn't mean they can't be used by mild/moderate hearing losses, they just normally aren't
ALDs - three categories (3)
▪ Assistive listening devices (ALDs) ▪ Telecommunication devices ▪ Alerting Devices
ALDs - broad definition
▪ Broadly defined, assistive devices are technologies (other than hearing aids and cochlear implants) that are designed to improve the communication abilities of individuals with hearing loss
ALDs: FM Systems - weaknesses
▪ Can be expensive ▪ Subject to FM interference (check carrier Hz) ▪ Privacy is not guaranteed—eavesdropping can occur ************************** ▪personal FM systems can cost as much or more than a hearing aid ▪it's ok if everyone in the same room has the same carrier frequency but it can get difficult when you start mixing them around
ALDs: Infrared Systems - large group systems (3)
▪ Can be used as a large group system in theaters and concert halls ▪ A single transmitter or several transmitters are strategically placed around the listening area to bathe the area with the modulated light waves ▪ Listeners with hearing loss obtain headset receivers and sit anywhere in the audience that there is a direct "line of sight" between the photodiode on the receiver and the LEDs on a transmitter *************************************************** ▪ the quality of the sound is really good for these ▪ we bathe the area with those light wave ▪ they have to be in the "line of sight" to one of the transmitters - ex: if a person is sitting in front of them and blocking them from the receiver
ALDs - group systems or personal systems (4)
▪ Can get group systems or personal systems ▪ Group systems are designed to be used by multiple individuals at once: - Classroom - An audience ▪ Personal systems are "owned" by an individual and are portable and move with the individual ***************************** ▪ people can own a personal ALD or there can be events/venues that have ALDs in group systems ▪ every classroom in some schools have ALDs - classrooms are a great place to have group systems - an audience ▪ personal systems are owned by an individual and are portable group systems are there and you have to have a way to connect your ear to it
Alerting Devices - see link
▪ Clocks, Timers, Watches and Alerting Systems https://www.harc.com/collections/alerting-devices
Telecommunication Devices
▪ Devices designed to assist a person with hearing loss to communicate on the telephone and to follow television programs are broadly classified as "telecommunication devices" ▪ Personal hearing aids can be used on the phone using either acoustic coupling or inductive coupling ************************************************* ▪ people can use telecoils (inductive coupling) or they can use the mic on their hearing aid ▪ acoustic coupling is just using the microphone of the hearing aid
DM (Digital Modulation)
▪ Digital sound transmission and digital sound processing ▪ Leads to fewer transmission dropouts and security in the transmission itself, since it is an encrypted digital signal. ▪ Wider system bandwidth ~ 100 to 7000 HZ, compared to analog FM. Digitally modulated sound utilizes ▪ Roger Pen *************************************************** ▪ digital is the way we do all amplification now ▪ there's a wider bandwidth so the fidelity of the sound is better ▪ Roger Pen is a really cool DM system that looks like a pen ▪ it's a wireless microphone that can be used as a type of ALD ▪ it's like a portable system ▪ instead of wiring the mic up to a big system you can just use it in any situation where you need amplification ▪ in the car, people complain that they can't hear when they're driving because they're not facing the people who communicate with them - the user can put it on a neck loop and have someone wear it if they want to talk to someone in the car or they can give it to a fitness instructor so they can hear - most children don't have the Roger pen, most children have the "boots" ▪ Roger Pen is a phonak device (a hearing aid company) but you can pair it with any type of hearing aid it also has a mini mic
ALDs: Infrared Systems - disadvantages (5)
▪ Disadvantages ▪ Lack of portability, confined to certain listening area ▪ Cannot be used outside due to interference from sunlight ▪ The LEDs and photodiode must be "line of sight" ▪ Reflected signal from solid surfaces may degrade sound quality ▪ Large area systems need professional installation ************************************************************* ▪ this just shows some different ways to couple the sound from the speaker/loudspeaker of the TV to the person ▪ a silhouette inductor is really just coils of wire placed in what looks like a BTE so it can be placed on the ear - for people who don't have hearing aids
ALDs: FM Systems - strengths
▪ Excellent sound quality ▪ Easy to use—no installation required for personal systems, but needed for SF systems ▪ Extremely versatile—can be used indoors or outdoors and can transmit through obstructions and around corners ▪ Several systems can be used in the same area as long as different carrier frequencies are used ▪ Not subject to electrical interference ▪ Receiver doesn't need to be in direct line with transmitter ▪ Different coupling options ▪ Personal HA - DAI - Telecoil - Neckloop - Other (Silhouette)
The Use of ALDs in the School System - FM Sound field Systems
▪ FM Soundfield Systems: ▪ Help improve the S/N, therefore these systems help all children hear better ▪ It is hypothesized that this will be especially beneficial to children with fluctuating hearing loss due to otitis media, children with ADD, children with unilateral hearing loss ▪ It is also hypothesized that this will help teachers fatigue—particularly vocal fatigue ************************************************************** ▪ there are also these desktop speakers ▪ kind of like the idea of the Roger Pen but the kid would walk around and carry a microphone and a speaker - he had some sensory issues and didn't actually want anything to be on his head
The Use of ALDs in the School System
▪ FM soundfield amplification can be found in many (especially newer) classrooms ▪ Designed not only with hearing impaired children in mind—instead, it is designed to provide an enhanced acoustic signal for all children in the classroom *********************************************** ▪ soundfield amplification - speakers are positions usually around the perimeters of the ceiling and space throughout the top of the wall ▪ the teacher's voice is essentially heard in the back of the room as well as it's heard in the front of the room ▪ this is a benefit for every child in the classroom ▪ 70-80% of children have ear infections so they're not heating consistently ▪ also works for kids who have attention problems ▪ even good for just a normal 5 year old to be able to hear everything ▪ Universal design ▪ designing products that are helpful to all people ▪ regardless of the person, you make a product that works for people with all kinds of issues ▪ vision, hearing , mobility, etc.
ALDs: FM Systems (3)
▪ FM systems have been used in classrooms since the late 1960s ▪ In 1982, the FCC lifted the classroom-only restriction—this allowed FM systems to become available for personal and group use in public facilities, like places of worship and auditoriums ▪ Today, these systems—both group and personal—are very popular, in large part due to their versatility ***************************************************** ▪ Some places use infrared, the quality is better BUT you have to be within line of sight from the transmitter ▪ FM stands for frequency modulated signals ▪ when we talk about personal FM systems now, they're almost always referred to as DM systems for digital modulations ▪ they're still frequency modulated but it's digital ▪ it would be more accurate to call them *DM systems*
Using Personal Hearing Aids - problems associated with acoustic coupling:
▪ Feedback ▪ Positioning can be awkward ▪ In the inductive coupling method, the person activates the telecoil in the HA ▪ For listeners who do not own HA, whose HA do not have a telecoil, or who have problems even using a HA compatible phone with a good telecoil, telephone amplifiers can be used *************************** - the advantage of inductive coupling, the microphone of the hearing aid is essentially turned off, the patients just hear what's coming over the phone
Television Viewing
▪ For individuals who have trouble understanding television programs, closed captioning (CC) can help ▪ The Television Decoder Act requires built-in decoders on all TVs with 13" or larger screens produced after 1993 ▪ Thus, TVs will include a built-in decoder ▪ Separate decoders can be purchased for older TVs or those with smaller screens—although these are becoming harder to find
ALDs: FM Systems - group systems
▪ Group systems found in classrooms and in many public facilities - In the classroom, the teacher wears a mic - The mic can be wired into a small battery-powered transmitter that is also worn or - The mic can be wireless and send a signal to an AC-powered transmitter ▪ In public facilities, the electrical signal from the public address system is typically used as the input to the FM transmitter *********************************************** ▪ this mic pack usually looks like a garage door opener and often teachers/speakers wear it around their necks
ALDs: Hardwire Systems - hardwire systems typically consist of (5)
▪ Hardwired systems typically consist of - A microphone that is placed near the source of the sound - An amplifier - A receiver that is at the ear of the listener ▪ All the components are connected via hardwire **************************************************************** ▪ we don't usually use wired systems in big venues anymore bc the cords would have to run around the room
ALDs - how do they help in adverse listening environments? (4)
▪ Help in adverse listening environments by: ▪ Placing the microphone of the system close to the signal of interest (e.g., the speaker's mouth, the public address system) ▪ Signal is then transmitted directly to the ear of the listener ▪ The signal can be transmitted using a variety of technologies (hardwire, induction, infrared, or FM) ▪ The ALD can be used with or without a HA *************************** ▪ most of the ones we fit now are not hardwired ▪ FM (frequency modulated) ▪ bluetooth is also a big way! bluetooth technology is getting a lot better!
Using Personal Hearing Aids
▪ In the acoustic coupling method, the listener simply holds the telephone receiver up to the microphone of the hearing aid ▪ Positioning is normal for custom instruments—it works particularly well for CIC instruments ▪ Positioning is toward the top/back of pinna for BTE instruments ********************************************* ▪ with custom instruments, you would hold it up to your ear like normal ▪ with an ITE the microphone is usually kind of right in the bowl, you might not be able to put the telephone right against the ear bc it might cause some feedback, they may have to hold the phone off the ear a little bit ▪ with a BTE, you have to put the phone up a little bit by the microphone
Using Telephone Amplifiers - see links
▪ In-line amplifier + neckloops https://www.harc.com/collections/telephone-amplifiers ▪ "Stand alone" amplified telephones https://www.harc.com/collections/telephones
ALDs: Induction Loop Systems
▪ Induction loop systems are wireless—they use an electromagnetic signal to transmit the signal between the speaker and the listener's ear ▪ When an electrical current is passed through a loop of coiled wire, an electromagnetic field is generated in the vicinity of the loop—this electromagnetic field varies in proportion to the current ▪ When a second coil of wire is placed in the vicinity of the varying electromagnetic field, an electrical current—identical to the one flowing through the original loop—is induced in the coil ******************************************************** ▪ if you have another induction coil in that same vicinity, they will communicate with one another ▪ one of he biggest issues: you can't be positive that the current is the same across the room
ALDs: Infrared Systems - personal use (5)
▪ Infrared systems are also available for personal use ▪ The most common application of personal infrared systems is for TV viewing ▪ The microphone of the system can be attached with Velcro fasteners to the speaker of the television (or can be obtained from the audio output jack if available) ▪ The transmitter is placed on top of the TV—facing the viewing area ▪ The listener wears the receiver and headset—or couples the output of the receiver to their HA ************************************************************* ▪ these are more popular than induction loops in the home bc these are something that they can take home and install it themselves ▪ as long as they have a direct line of sight with the tv they're good ▪ if you're doing a big venue obviously it would need to be professionally installed
ALDs: Infrared Systems - advantages (3)
▪ Infrared systems typically provide exceptional sound quality ▪ Infrared systems are the system of choice when confidentiality or copyright restrictions are a consideration — infrared light waves cannot penetrate walls or thick curtains ************************************************ ▪ infrared light can't travel through walls, or even really thick curtains ▪ so whatever's in that room, stays in that room
ALDs: Infrared Systems (3)
▪ Infrared systems use harmless light waves outside the boundaries of visible light to transmit sound ▪ An AC-powered transmitter (called an emitter) uses the electrical signal from the microphone to modulate an invisible light wave (95MHz) ▪ The light wave is transmitted throughout the listening area by special light-emitting diodes (LEDs) located on the front of the transmitter
ALD: Induction Loop Systems - disadvantages (5)
▪ Lack of portability ▪ Strength of magnetic field decreases with distance - If system installation isn't handled well, there are "dead" spots ▪ Subject to electromagnetic interference (i.e computers) ▪ Fidelity affected by telecoil strength and orientation ▪ http://hearingloop.org/ *********************************************** ▪ there's usually some dead spots even with a good installation, so when you have a bad installation there are a lot of dead spots ▪ electromagnetic interference - if there's a computer in that region, people complain that they hear a buzzing noise from the computer ▪ the fidelity of how the system works, it depends on how the loop is installed, and how the telecoil is positioned in the hearing aid ▪ hearingloop.org promotes "looping America" - see website for sound demos - anytime there's a looped area, they should have a sign that should indicate that you can turn your telecoil on and access the induction loop system
ALDs: Hardwire Systems - Large area systems (4)
▪ Large area systems have been used in public facilities like places of worship and theaters - The microphone can be placed at the speaker's podium or tied into the public address system - The electrical signal from the microphone is boosted by the amplifier and routed through wires (which can be concealed under carpets) to specific listening areas - The listener with hearing loss can plug in headsets or couple the system to their HAs
ALDs: Hardwired Systems - strengths (3)
▪ Low cost ▪ Can have good sound quality (one-to-one) Simple to operate
Using TTYs
▪ Many HI people cannot converse on a telephone even with HA or telephone amplifiers ▪ Some have severe to profound hearing loss ▪ Some have severe speech understanding problems ▪ Some have severe speech production problems ▪ These individuals can use a TTY https://www.harc.com/collections/tty-vco ********************************************************* ▪ teletype phone ▪ these are becoming less and less popular because of things like facetime, video conferences, texting, etc. ▪ texting is much better for people with hearing loss - the only way you could use that TTY to TTY is with someone else who has a TTY - the user of the TTY can call a service in the state, they can have them call the person they want to talk to and relay the message ▪ service animals - aren't as common for hearing impaired as other disabled people but they are an option
ALDs: Delivering the Signal from the Device to the Listener
▪ Most ALDs can deliver the signal to the listener in two different ways ▪ By coupling the signal from the receiver to special headphones, which are worn by the listener ▪ By delivering the signal from the receiver to the listener's personal hearing aid ********************************************************** ▪ why do you think delivering it through the hearing aid is a better option for a hearing impaired person? - if a child uses their own hearing aid, everything that comes through the FM system is going to be shaped in a way that is specific to that kid's specific hearing loss so it's always better to have them use it through their own hearing aid
ALDs - most common HA user problems (6)
▪ Most common HA user problem: Listening in conditions that are less than ideal—at a distance, noise, reverberant conditions ▪ These situations are difficult because: - Signal arriving at HA microphone is reduced in intensity (because of the distance it has traveled) - Signal is mixed with background noise present in the environment - Signal is degraded by reverberation ▪ A HA alone (even advanced digital HA) cannot completely resolve these problems ************************* ▪ remember we talked about adaptive directional microphones ▪ those try to focus on what the hearing aid identifies as speech and not focus on what is noise ▪ how does it do that? - speech is a dynamic signal that has constant variations in frequency and intensity - a steady state noise usually stays pretty consistent in its frequency and intensity - that works really well except when the noise is also speech ▪ ALDs are really meant to help people with even the most high-tech hearing aids ▪ every single patient is not going to need an ALD, bc it depends on their lives - some patients are really going to benefit, and we should be able to recognize it - SLPs should be able to recognize when to be able to make a referral to an audiologist when a hearing aid patient is still struggling
ALDs: Induction Loop Systems - advantages? (2)
▪ No special receiver is needed if the listener has a HA telecoil ▪ Smaller systems are not overly expensive, although professional installations are required for large systems=expensive *********************************************************** ▪ the professional installation needs to be done well ▪ if the current isn't good there will be a dead spot ▪ if you wanted to do multiple loop systems in your house, there's not going to be that much interference because those fields are separated, but there probably is some rule about how much distance needs to be between them
ALDs: FM Systems - who are personal FM systems used by (3)
▪ Personal FM systems are very versatile, so they can be used for a variety of applications ▪ By a child mainstreamed into classes of children with normal hearing ▪ By adults who need an improved S/N ****************************************************** ▪ when might a child with normal peripheral hearing want to use an FM system? Why would we recommend that? ▪ kids with ADHD , it really helps them focus ▪ the disadvantage for a personal system with them (the headphones can be a bit distracting) ▪ auditory processing disorders would be a great candidate for an FM system ▪ anytime an adult or a child needs an improved s to n ratio
ALDs: FM Systems - Personal systems are hardwired PAS
▪ Personal FM systems can also be used as a more expensive (and slightly more complicated) version of the hardwired PAS—e.g, ▪ As a substitute for a body style hearing aid for individuals who are bedridden or who have vision and dexterity problems ▪ As a tool in health care facilities to be loaned to individuals who don't own a personal HA to facilitate communication *********************************************************** ▪ PAS - personal amplification system ▪ for someone who feels like they can't maneuver a hearing aid or feel like they don't want a hearing aid
ALDs: Hardwired Systems - PASs (5)
▪ Personal hardwire systems are often referred to as PASs (Personal Amplification Systems) ▪ These devices can be used as an alternative to hearing aids - They are relatively low cost - They can have good sound quality - They are easy to operate and have large, accessible controls **************************************************************************** ▪ some of them have really good sound quality - depends on who makes them ▪ these are good alternatives for people who are bedridden or people who are physically/mentally not able to operate a hearing aid ▪ they typically look like a wire with earphones connected to a box - the microphone is on that box and they can adjust the volume they leave them out on the wheelchair or in their pocket they put the box near the speaker or the TV and they put the headphones on
ALDs: Hardwired Systems - personal hardwire systems (4)
▪ Personal hardwire systems work in much the same way—just on a smaller scale - The mic of the system is placed near the sound source (the talker, TV, etc.) - The signal is sent to the amplifier, where the volume can be varied using a volume control wheel - Amplified signal is delivered to the listener's ear—typically using a lightweight headset or earpiece ********************************************************** ▪ usually with a set of headphones or some kind of earpiece
ALDs: Delivering the Signal from the Device to the Listener - what is DAI a means of? (3)
▪ Recall that DAI is a means of delivering an electrical signal directly to a hearing aid ▪ The signal from the ALD receiver is sent via cord to the hearing aid ▪ An audio "shoe" or "boot" is snapped on to the bottom of a BTE hearing aid and is wireless
Using TDDs
▪ TDD stands for Telecommunication Device for the Deaf (aka TTY "teletype" machines) ▪ Some prefer the term Text Telephone (TT) since individuals other than those who are "deaf" often make use of the device ***************************************************** - some people prefer text telephone
Using TDDs - TDDs consists of three parts
▪ TDDs typically consist of three parts ▪ A keyboard for typing the outgoing message ▪ A coupler (or modem) in which the handset is placed to send and receive the message ▪ A display where the incoming message is shown
ALDs - telecommunication devices (3)
▪ Telecommunication devices are used to improve communication over the phone or to aid in understanding the signal coming from the TV ▪ Some telecommunication devices provide an enhanced auditory signal (like a telephone amplifier) ▪ Others provide a visual signal in addition to or in place of the auditory signal (like a TDD for the telephone or a closed caption system for the TV) *********************** - All TVs have closed captioning on - it's good for lots of different types of people, not just hearing impaired
Using Telephone Amplifiers
▪ Telephones can be amplified in a variety of ways ▪ The amplifier can be built into the telephone itself ▪ The amplifier can be built into a replacement handset (simply replace the original handset with one that amplifies the signal) ▪ The amplifier can be placed "in-line" between the telephone and handset ************************************ - those are rare now, although some offices may have them still "line-in" aka "in-line" amplifiers
ALDs: FM Systems - FM signal
▪ The FM signal is broadcast through the listening area—so individuals can sit anywhere in the room ▪ Listeners who wish to use the system use an FM receiver to demodulate the signal ▪ In a classroom, the child will have their own receiver that is adjusted for their HL ▪ In a public facility, the person can pick up a receiver that provides a broad frequency response and a manual volume control ▪ The output from the receiver is delivered to the listener using headset or the listener's HA ******************************************************** ▪ it isn't meant for certain hearing losses ▪ it has a broad frequency response and you can adjust the volume to what you need it to ▪ degree of HL is another story bc there is a limit of how loud those can go - it isn't always about loudness for people with SN HL, it's about clarity
ALDs: Delivering the Signal from the Device to the Listener - advantage to using a personal hearing aid
▪ The advantage to using a personal hearing aid is that it allows the signal from the ALD receiver to be amplified and shaped to meet the individual's needs ▪ Using the hearing aid telecoil ▪ Using a direct electrical connection between the ALD receiver and the HA ****************************************************** ▪ a lot of times people who need ALDs don't use hearing aids ▪ a lot of times it takes 7 years between the time someone knows they have a hearing loss and the time they seek some kind of intervention/treatment ▪ we typically use this audio shoe or boot
ALDs: Delivering the Signal from the Device to the Listener - without a hearing aid
▪ Without a HA, can use different transducer styles: ▪ Lightweight earphones (with headband) ▪ Earbuds (which fit into concha area) ▪ Under the chin style headsets—often used with infrared systems ▪ Small body aid-style hearing aid receivers (which snap into the standard-style earmold) ******************************************************** ▪ often we will talk to people about infrared systems that they can easily set up in their homes ▪ audiologists don't set this up but they can give names and numbers of people who can ▪ as SLPs you need to know that these options do exist for patients
Induction Loop Systems - schematic
▪ you don't see the wire that goes around the room ▪ it's usually hidden along the wall/carpet ▪ anyone with a telecoil can go into that room and turn their telecoil on ▪ you can also get something to put over your head if you don't have a hearing aid ▪ people can borrow one of those loops and put it over their head ▪ this is most popular now in churches
