Hearing loss may interfere with daily communication on many occasions. A hearing aid usually helps, but some situations may still present a problem. It might be difficult listening in a noisy restaurant or in a business meeting where the speaker is at a distance from the listener. The telephone can present a special problem where even a hearing aid is not of help. Doorbells or safety alarms are other areas where special assistance may be helpful. There are many assistive communication devices for the hearing impaired. Their selection should be individualized relative to the magnitude of the hearing loss and the person’s lifestyle. Information concerning these devices can be obtained from your ear physician, audiologist, or hearing aid dispenser.
Types of assistive devices include:
- Telephone amplifiers
- Telephone devices for the deaf
- Radio/television amplifiers
- Signaling devices
- Personal amplification systems
- Devices for professional people
Hearing impaired people often complain about problems using the telephone. Many hearing aids have a switch (“T”) which activates a telecoil. This helps to eliminate background noise and the feedback which occurs when the telephone receiver is held near a hearing aid. The user can adjust the volume of the hearing aid in order to hear the party on the phone. Unfortunately these coils are not available for all aids and are not compatible with all telephones or the signal may be too weak to be effective.Telephone amplifiers to increase the loudness of the telephone signal may be portable or built into the receiver of the telephone. They usually have a volume control that enables the user to adjust the signal to a comfortable level. Portable amplifiers ($20-$100) may be carried in a pocket or purse and attached directly over the ear piece of the telephone or connected on the cord of the phone receiver. These are battery powered. Non-portable amplifiers are built into the handle of the telephone and have an adjustable volume control. These are usually available through the phone company.
Telephone devices for the deaf (TDD/TTY) were originally teletypewriters like those used by the news services to transmit information over telephone lines. Current Telecommunication Devices for the Deaf, TDDs, allow a severely or profoundly deaf person to directly call another person having similar equipment. They are available in various styles and sizes. Some are portable, semi-portable, or desk models. Messages are displayed on a visual screen, and some TDDs have a paper printout for a permanent record of the conversation.
Some individuals with a high frequency hearing loss may find it difficult to hear the ring of the telephone, smoke alarm or doorbell. They may have the standard high pitched sound replaced with a lower tone bell or buzzer. In addition some find it helpful to have a visual alert on these devices so that when they sound, a light will flash or a fan will turn on.
Television, Radio and Stereo Amplifiers
Listening to the television or radio in the presence of background noise is often frustrating for the hearing impaired person. In addition, the loud volume of the television may be bothersome to normal-hearing members of the family. With the use of an assistive communication device, the hearing impaired person may listen to the television, radio or stereo at a comfortable loudness without interference of background noise.Devices may connect to a hearing aid with direct audio input, (headphones that connect to the listening jack of the TV), listening loops for use with the telecoil on a hearing aid, or wireless infrared devices that send the audio signal directly to the listener via a receiver. The infrared systems ($180-$350) are high fidelity systems which convert the audio signal into infrared waves (invisible light beams). The infrared transmitter is plugged into a wall socket, and the microphone is fastened with Velcro to the front of the television speaker. The headset is lightweight and comfortable and has volume control. The headset converts the infrared energy back to amplified sound. These systems are commonly used by the hearing impaired in theaters and churches.
The components of an “audio loop system” are a microphone, an amplifier, and a length of wire which loops the seating area. Some loops are connected to standard public address systems. The electric current flowing through the loop creates a magnetic field that can be picked up by a hearing aid set on the T-switch. Portable receivers are available for hearing impaired people without a hearing aid T-switch. To pick up the signals, hearing impaired listeners must sit within or near the loop.
FM (frequency modulation) systems ($400-$1,200) can be used alone or with hearing aids which have a “T” switch or audio input. They work by sound being picked up by a battery operated microphone at the source and transmitted via a tiny wireless FM radio directly to earphones worn by the hearing impaired person. This method delivers high quality sound and reduces interference caused by background noise. It is suitable for hearing a person speaking, TV and radio. Since the transmission can occur over a 300 foot range, it is also ideal for large group gatherings. An FM receiver enables the user to leave the immediate area of the signal and still receive sound clearly.
Television caption units insert subtitles onto the screen for many of the popular television programs. This allows the severely hearing impaired to understand the audio portion of the program by reading the subtitles. These closed captions can be seen only on a television set with a decoding device ($220-$300).
There are many signaling devices which can visually alert the hearing impaired person to auditory signals that may not be heard. Most of these devices automatically flash a light to alert the person to the sound source. Others activate a vibrator to wake a person who is sleeping. Signaling devices may be purchased individually, as with a telephone ring indicator, or in a complete alert system which monitors phone, door, fire alarm, and even a crying baby. Alarms awaken the hearing impaired with a flashing light or a pillow vibrator to massage a pillow.
Personal Amplification Devices
Many hearing impaired people have difficulty hearing and understanding in the presence of background noise. Listening in groups, meetings, or theaters can be affected by noise interference, room reverberation, and the distance from the speaker. Devices are available which will increase the loudness of the person talking without amplifying the background noise. These may be useful in a conference room, restaurant, party, or similar noisy environments. Simple versions include a directional microphone attached by a wire to an earphone. More elaborate systems are wireless and may be clipped to the speaker’s lapel or placed anywhere in the room. These systems transmit the sound either by infrared or FM signals. A loop induction system can be installed in a room so that all of the microphones in the room transmit both by auditory and induction signals. In this way those with hearing aids can use the “T” switch in the aid to pick up only the sound from the speaker and not the background noise.
Devices for Professional People
Many professionals who do not use hearing aids require some amplification in special situations. The physician, for example, with a mild hearing loss may benefit from an electronic stethoscope. A nurse in a convalescent home who provides services to hearing impaired people may find a portable amplifier useful to establish quick communication with non-hearing aid users.