Technology and assistive devices can be credited with much of the improved access to mainstream society experienced by people with disabilities, but the promise for tomorrow hints at participation not even dreamed of a generation or two ago. Minda Huebner (2002) helps us see into the future. "In my vision of tomorrow's world, I see many technological advancements that will ... enable people with hearing loss to understand things that do not have lips, televisions, telephones, and intercoms" (p. 9). Here some of the advances she envisions:
- Special glasses that show movie captions that are invisible to everyone else
- Telephones that show the words of conversations on mini-screens
- Waterproof hearing aids that let everyone participate in water fights, soccer in the rain, and swim meets
- Home computers that make all of the lights in the house flash and alarm clocks vibrate when the smoke alarm goes off
- Lights on all cars' dashboards to indicate when an emergency vehicle is near
Clearly, the possibilities are endless, but barriers can make it impossible for many to experience Huebner's dreams about tomorrow. The costs of assistive devices although they decrease across time, limit people's access to helpful equipment. As you might imagine, cost is a major issue for people who are deaf or hard of hearing; many are unable to afford improved hearing aids or the wide range of devices that would help them. Government agencies are usually not of much assistance (Trychin, 2001). Assistive devices can be grouped into four categories:
- Assistive listening devices
- Telecommunication devices
- Computerized speech-to-text translations
- Alerting devices
Assistive Listening Devices
Assistive listening devices help people with hearing losses by increasing the amplification of sounds in the environment, including others' speech. Three general types of assistive listening devices are available: hearing aids, cochlear implants, and FM transmission systems. Read What IDEA '04 Says About Hearing Aids an Cochlear Implants to learn about some specific federal guidelines for two of these assistive listening devices.
Most conductive losses can be corrected with medicine or surgery, so people who use hearing aids—assistive devices that amplify sounds but are not surgically implanted—typically have sensorineural hearing losses. The hearing aid is the most commonly used assistive device for this group of people; it amplifies sound so that the person can hear more easily. These assistive listening devices have improved greatly over the years. Today's hearing aids allow many individuals to hear well within the normal range. These devices have eliminated the need for special ed cation for many children who are hard of hearing; with their hearing aids, they can profit from general education classes and participate fully in mainstream society Four different kinds of hearing aids are available:
- Behind the ear (BTE)
- In the ear (ITE)
- In the canal (ITC)
- Completely in the canal (CIC)
Because appearance is particularly important to children and teenagers, few select BTEs, even though they tend to be somewhat more effective than those that are hidden in the ear. Many hearing aids are digital and are designed to address each individual's hearing profile. Digital hearing aids automatically adjust volume by amplifying sounds only to the degree necessary to compensate for the loss at each frequency of sound. They also significantly reduce background noise. Older analog models amplify all sounds equally, making it impossible to discriminate speech from noise. A new type of hearing aid is gaining in popularity, possibly because of issues related to keeping hearing aids clean and undamaged. The Songbird Disposable Hearing Aid (SDHA), which now also comes in a digital version, costs about $1 per day it is worn (Ross, 2002). Certainly, disposable aids have great advantages for children, who often damage their aids and find it impossible to keep them clean. Teachers and parents must recognize, however, that hearing aids do not solve all problems associated with hearing loss. Even when hearing aids are carefully matched to and programmed for the individual, they do not completely overcome the limitations of an impaired ear (Ross, 2002; Sweetow & Luckett, 2001).
Another type of assistive listening device helps those with sensorineural hearing losses access the world of sounds. Cochlear implants are surgically implanted devices that use a small speech processor and microphone to detect sound and then send electrical signals to the implanted receiver/stimulator, which stimulates the ossiscles and the the cochlea, passing information on through the auditory nerve to the brain. A typical cochlear implant converts acoustic information to electrical signals that stimulate the individual's remaining auditory nerve fibers. Since the U.S. Federal Food and Drug Administration approved cochlear implants in 1990, great advances have been made (NIDCD, 2002b). Originally thought to hold the promise of "bionic ears," they first were used only with people who experienced severe hearing losses later in life. These individuals have already developed the ability to understand speech and language, so their experiences with implants are very different from those of infants and young children with congential deafness who have not yet learned process and understand sounds. Because research is showing that individuals who received implants before the age of 2 have better expressive language than those who receive implants later, infants as young as 1 year now receive implants (Bergeson, Pisoni, & Davis, 2003; Kirk et al. 2002). Even so, the verbal abilities of most "implanted" preschoolers lag behind those of their peers without hearing loss (Chin & Kaiser, 2002). It is important to put these data into perspective: Relatively few infants and toddlers have received implants, and their surgeries were recent. In 1997, a total of 8 children 18 months old or younger have received a cochlear implant (Sorkin, 2002). That number had risen to 90 in 2000 and to 149 in 2001. It can take years before implants actually provide their intended benefits. because the brain has to learn to translate the electronic impulses generated by implants into meaningful messages (Marschark, 2001). Much, therefore, remains to be learned about implants and children.
Background noise is a major problem in many classrooms, lecture halls, theaters, auditoriums, recreational centers, cafeterias, and other large rooms (Smaldino, 2004). FM (frequency-modulated) transmission devices overcome the distance and noise problems that nearly always arise in general education classrooms (Halligan, 2003). New versions of this technology use small devices, which provide freedom of movement for both teacher and students. The teacher speaks into a small microphone either clipped to a shirt or worn lavaliere style (as a pendant on a chain). Students receive sound through a small receiver connected directly to their hearing aids. Background noise is reduced, and teachers are free to move around the classroom without ,worrying about having their faces in full view of all their students. For large rooms such as lecture and concert halls, another solution is the audio loop, which routes sound from its source directly to the listener's ear through a specially equipped hearing aid or earphone. Sound may travel through a wire connection or through radio waves. Audio loops are inexpensive and are easy to install in rooms that seat up to 100 persons. Since passage of the ADA law, audio loops are found in most concert halls, theaters, airports, and churches, giving people with hearing loss greater access to events. Of course, such sound systems benefit only those individuals who profit from amplification.
What's on the horizon? Blue Cross Insurance Company now approves, for reimbursement, surgically implanted hearing aids that cause the middle ear bones to vibrate and thereby transmit sound to the inner ear (Blue Cross of California, 2004). For those with moderate to severe sensorineural hearing losses who find that hearing aids are not effective enough, these middle ear implants provide about 85 percent improvement in hearing and do not amplify distracting background noise as they increase the individual's ability to hear speech (Wagner, 2002). Clearly, the use of these devices will become commonplace in the near future. Other research efforts will not yield results that can be applied for pubic benefit for many years to come. Here's an example: Although some animals are able to regenerate hair cells automatically and regain the ability to hear, these cells do not regenerate automatically in humans (Uffen, 2005). About 80 percent of irreversible hearing loss is caused by damage to the hair cells in the inner ear. Researchers have been able to make hair cells regenerate experimentally, but getting the right hair cells to grow in the proper numbers remains challenging (Bauman, 2004). Ev.en so, this potential medical technology holds promise for what may become a way to treat this type of sensorineural hearing loss (Vanderhoff, 2003).
Telecommunication Devices
Assistive telecommunication devices are designed to improve access to and enjoyment of cinema and television through sight. Many different types of telecommunication devices and systems help people with hearing loss. For example, captions are printed words that appear at the bottom of a TV screen (like the subtitles that translate dialog in foreign films or the ticker seen on news shows). "The French Chef with Julia Child" was the first captioned television show, appearing on public television in 1972. It used open captions, which are seen by all viewers, but they were unpopular with the general public. In the 1980s another system was developed. Closed captions uses a system that allows the viewer to choose whether the captions are seen on the TV screen. All television sets sold since 1993 are equipped with an internal, microsized decoder that allows captions to be placed anywhere on the screen (to avoid interfering with on-screen titles or other important information in the program) and to appear in different colors. Nearly all TV programming today includes the option of viewing closed captions. Captioning is an important tool for people who are deaf, because it affords them equal access to public information, emergency broadcasting, and entertainment. Data indicate that deaf people use captions. They spend some 84 percent of their viewing time reading the captions, 14 percent watching the video picture, and only 2 percent not watching the video (Jensema, Danturthi, and Burch, 2000). Captioning has been much slower in coming to the movie theaters, and people with profound hearing losses have had to wait to see films until they are available in captioned DVDs. However, experiments with different captioning systems for movie theaters are moving forward. For example, rear window captioning (RWC) projects captions from a message board on the theater's rear wall onto a clear plastic screen that attaches to the moviegoer's seat; the individual looks at a transparent Plexiglas panel to see the captions and forward to see the movie.
Another important assistive device enables those who are deaf to make and receive telephone calls. The text telephone (TTY), formerly referred to as the telecommunication device for the deaf (TDD), prints out the voice message for the person with a hearing loss and can also be used to send messages. Most TIYs have one major drawback: A unit is required at both the sending and the receiving end. There are two solutions to this problem. First, the Federal Communications Commission requires all states to have a telecommunications relay service (TRS), which allows a TIY user to "talk" to a person using a standard phone. An operator at a relay center places the call on a voice line and reads the typed message from the TTY to the non-TIY user. The relay service enables deaf individuals to use the phone, via an 800 phone number, for everything from calling a doctor to ordering a pizza. Most people who are deaf or hard of hearing prefer to use their voice on a phone call, and a new device is now available. The voice carry over (VCO) is a TIT that includes the option of using both voice and text. For those who want to use their voices but need to receive telephone communication through print, these phones allow for both voice and text transmissions. A relay operator types what the hearing person says, which is then displayed on the text phone. VCOs have many advantages, particularly for hearing people with deaf family members or friends, for businesses that want both options but do not want to invest in two different phones, and for public places so that everyone has access to the telephone system. For those , ho want quicker response times and the option for both parties to talk at the same time, a two-phone-line VCO system is now available. And there is even a TTY/voice answering machine that takes messages in either format.
The demand for TIYs is decreasing because of technology designed for use by the general public. For example, more and more people with hearing losses communicate with family, friends, and business associates by using e-mail. Network-enabled personal data assistants (PDAs) are devices that allow the user to send text messages, use e-mail, and access the Web via wireless telephone systems. PDAs are reducing the need for TTYs. For all users, PDAs can vibrate with each incoming communication, allow for immediate responses that are typed, and free people from specific locations to send and receive messages.
Speech-to-Text Translations
Workers with profound hearing losses attending conferences and meetings often experience the same frustrations as college students during college lectures. It is difficult to take notes and read lips or watch a sign language interpreter simultaneously. Real-time captioning (RTC) can help deaf people in such situations. Several systems have beer; developed. C-Print® can translate up to 300 words a minute and is the fastest translation system currently available. CCPrint® uses a laptop computer, a specially developed wore abbreviation software program, and a computer visual display. The trained C-Print® captionist listens to the lecture and types codes that represent words into the computer; the transcription is instantly shown on a monitor or on the individual's laptop. It is ideal for lectures (Stinson et al., 2001). Once the lecture is completed, students can also get a printout—a benefit that lots of class members can appreciate. Many students who attend traditional colleges and universities, and who would otherwise have to rely on an interpreter. report that RTC does not make them feel different and even improves social interactions (Kramlinger, 1996).
Another system that might solve problems associated with accessing the general education curriculum, which relies heavily on oral communication (at least for those who have good reading abilities) , is technology-based speech-to-text translations. Automatic speech recognition (ASR) is technology that enables the computer automatically to convert speech at rates below 160 words per minute into text with error rates of less than 3 to 4 percent (Davis, 2001). ASR was developed for dictation, so the system does nor recognize multiple speakers and is not beneficial for group discussion periods. Regardless, the benefits to persons with hearing disabilities are great.
Alerting Devices
Alerting devices make people who are deaf aware of an event or important sound in their environment via a loud noise or the sense of sight or touch. A loud gong, flashing light, or vibration can signal a fire alarm, doorbell, alarm clock, or telephone. Some such devices attach to a lamp that flashes on and off for a signal. Others attach to vibrators (in the bed for an alarm clock or on a person's belt as a personal signaler). Some alerting devices include sound-sensitive monitors that let the deaf person know about a baby who is crying or about an out-of-the-ordinary sound. Some such systems are now wireless, allowing great flexibility in placement of these devices and in the number of them that can be activated at anyone time (Vanderhoff & Lakins, 2003).