churchexecutive.com | $5.00 SEPTEMBER.2013
ebook:
Improving Church Accessibility
USL’s new Caption Glasses
Table of Contents p3
About USL Company Profile
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Hearing Impaired Audio
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Hearing Impaired Audio Transmission
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Hearing Impaired Audio Delivery
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Visually impaired – Narrative Audio
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Closed Captioning
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USL Products
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Improving Church Accessibility Religious entities are exempt from the construction requirements of the Americans with Disabilities Act (ADA) (see 28 CFR 36.102(e)). However, it is in the interest of churches to be as inclusive as possible. “Auxiliary devices” are available to assist hearing and visually impaired members of your church. This article concentrates on Assistive Listening Systems, which can assist both hearing and visually impaired individuals and includes additional information on closed captioning.
About USL Ultra Stereo Labs (USL) is a major manufacturer of equipment for the cinema industry. USL’s product line includes Assistive Listening and Closed Captioning systems for the cinema industry. These systems also find wide application in other venues, such as courts, churches, etc. Hearing Impaired Audio Hearing impaired (HI) audio is generally a “dialog-centric” copy of the main audio with reduced dynamic range. In a church application, this would generally be audio from the public address system that includes microphones used by individual speakers with other content (music, etc.) either absent or at a reduced level. In many applications, this is simply the PA system output. The “reduced dynamic range” is achieved through “compression.” Compression makes loud audio less loud and soft audio louder, evening out the overall sound level. USL assistive listening systems include an audio compressor. The hearing impaired audio is transmitted to the audience using magnetic induction, radio frequency, or infrared. The user can hear the audio directly using headphones or hear the audio through a hearing aid via magnetic induction or a direct (electrical) audio interface. Hearing Impaired Audio Transmission Three methods are commonly used to deliver HI audio to audience members. These are magnetic induction, radio frequency (RF), and infrared (IR). With magnetic induction, a several turn “loop” of wire is placed around the listening area. This loop is driven with a power amplifier with the HI audio. This generates a varying magnetic field representing the HI audio. The magnetic field induces audio into the telecoil (“T-coil”) within a listener’s hearing aid. A T-coil is designed to receive the stray AC (alternating current) magnetic field from a telephone receiver. In this manner, the audio is inductively coupled to the hearing aid instead of being acoustically coupled. Loop systems allow the transmission of one audio channel and may suffer from interference from power wiring in the building. While the one-channel limitation appears minor in church applications, churches may wish to use assistive listening systems to deliver a descriptive narration to visually impaired members or deliver a simultaneous translation of the speaker to those members who do not speak the primary language of the church. With radio frequency transmission, a small radio transmitter transmits the HI audio. These transmitters have traditionally been analog (using frequency modulation in either the FM broadcast band or on other frequencies where license-free operation is allowed). More recent transmitters use digital signals, sometimes encrypting the audio so it can only be received on authorized receivers. Cinemas often have several adjacent auditoriums, and interference between auditoriums is a concern. A patron may hear the HI audio for the movie in a different auditorium. This is generally not an issue for churches, but the receivers used in RF-based systems are a bit more complicated to operate due to their multi-channel capability. With infrared transmission, the HI audio is transmitted by an IR emitter. In a cinema application, these are mounted on the rear wall and pointed at the screen so the IR is reflected off the screen to all audience members.
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USL’s Listening assistive emitter panels and headset receivers.
In church applications, the IR emitter is usually mounted high in the front of the hall, either in the center or in a corner. By mounting the IR emitter in one of these locations, all members can see the emitter, and all the IR receivers can receive the signal. The IR signal also reflects off other surfaces in the room to allow reception by receivers where the emitter is not visible. The IR signal can carry multiple audio channels (and generally carries two, one for hearing impaired audio and the second carrying either a descriptive narrative for the visually impaired or a second language). Since fewer channels are required than with RF receivers, the receivers are simpler to operate. Note that the sun is also an IR emitter. Direct sunlight can interfere with IR transmissions, so IR systems are not suitable for outdoor venues. Hearing Impaired Audio Delivery Once the audio is transmitted into the hall using magnetic induction RF, or IR, it needs to be received and delivered to the user. Magnetic induction systems may use T-coil-equipped hearing aids as the receiver. As such, users with these hearing aids arrive with their own HI receiver. As noted previously, hearing aid T-coils are designed for use with a telephone. A telephone receiver radiates a DC magnetic field (from its permanent magnet) and an AC magnetic field (with the audio). Some current hearing aids automatically enable the T-coil by the presence of the DC magnetic field. Since a loop system only creates an AC magnetic field, this automatic activation does not work. If the hearing aid does not have a manual switch to enable the T-coil, the loop system will not deliver audio directly to the hearing aid. In this case, headphones, as with the other systems described below, are required. Magnetic loop receivers are available to drive headphones under these circumstances. RF and IR systems both deliver HI audio to headphones. The receiver may be built into the headphones (as the USL receivers are) or may be separate (common on RF linked systems). All receivers have the 1/8-inch monaural output jack currently required by ADA Guidelines. Headphones can serve the hearing impaired with and without hearing aids. For those without hearing aids, the louder dialog-centric audio allows them to understand the speech without the distraction of background noise and reverberation. For those with hearing aids, the headphones emit both a DC and AC magnetic field, so the automatic T-coil in a hearing aid can be enabled. In this case, the headphones are placed over the hearing aids instead of over the ears, just as a telephone would be when driving a T-coil. Placing the headphones over the hearing aid improves the magnetic coupling with the hearing aid and reduces the acoustic transmission into the ear where it may interfere with the audio created by the hearing aid. As mentioned, all HI receivers include a 1/8-inch monaural jack carrying the receiver audio output. This may drive the Direct Audio Input of hearing aids or implants. It may also drive inductive neck loops. An inductive neck loop creates an AC magnetic field, similar to that emitted by a room loop or headphones. However, as with room loops, there is no DC magnetic field, so automatic T-coils will not be enabled. Neck loops can be used if the hearing aid has a manual switch to enable the T-coil. One concern with headphones is sanitation. Several methods of handling this issue exist. 1. Headphones can be wiped with an anti-bacterial wipe. 2. Headphone ear pads can be replaced. 3. Users can purchase the headphones for their own use. Note that the 2.3MHz IR headphones are compatible with consumer IR headphone systems such as the TV-Ears 5.0 system. Members can use their headphones both at church and at home. 4
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Visually Impaired – Narrative Audio Visually Impaired – Narrative (VI-N) is an oral description of what is happening. VI-N audio is now commonly available in movie theaters. The VI-N audio allows movie patrons with visual impairments to enjoy a movie. Churches that do plays or have other activities where a description of the action would be useful could make use of VI-N audio. Since the action is live (instead of recorded, as in a movie), someone would need to voice the VI-N description during the action. Churches that do not need VI-N audio can still make use of a second audio channel to serve those who speak another language. As with VI-N audio, church applications would probably require a person to do the simultaneous translation and speak it into a microphone driving the VI-N transmitter. Closed Captioning Many movie theaters now have closed captioning systems. The U.S. Department of Justice is considering rules to require captioning in movie theaters. Captions are similar to subtitles but serve a different purpose. Subtitles are used to provide a language translation; captions translate sound into text for the hearing impaired. For example, a caption would indicate that music is playing or a telephone is ringing while subtitles would not. Captions can be “open” or “closed.” Open captions are visible to all. Closed captions are visible only to those with special receivers (or similar). Churches can serve the severely hearing impaired with open or closed captions. One “open caption system” that is available to live venues such as churches, but not movies, is the use of an ASL (American Sign Language) Signer. This person provides simultaneous translation of the spoken word to ASL so the speech can be “heard” by the severely hearing impaired. Another “open caption” approach available to churches is the use of a computer projector. A movie screen is placed somewhere in view of the members. A computer drives the projector to make text visible on the screen. The text can be from a file (a prepared speech), generated by a person typing as the talk progresses or with speech-to-text software. Because of the difficulty of typing at normal speaking speeds, it is common to use a “stenotype” keyboard on live captioning systems. This is the same keyboard used by court reporters. Special software converts the stenotype data to text for display. Closed captioning systems provide some sort of private display to the users so the captions are not visible to the general audience. Three closed caption display technologies are currently in use. The Mopix® Rear Window® system uses an LED sign on the rear wall of the hall. The sign displays the caption text, but reversed (right to left). The user views the text through a reflector. Use of the reflector corrects the direction of the text, allows the user to face the front of the hall, and makes the text invisible to other users (unless they have eyes in the back of their heads).
CCH-100 Closed Caption Eyewear from USL, Inc.
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The second type of closed caption receiver is a small receiver with a display. The user positions this display so it is in the line of sight, allowing both the captions and the front of the hall to be viewed. These receivers often include special optics so the displayed text appears more distant than it actually is. This avoids the need for the user’s eyes to refocus between near and far. The third type of closed caption receiver is a special pair of glasses that includes a small display. These glasses superimpose the caption text on whatever the user is viewing. Glasses tend to be more fragile than other receivers and need to be sanitized between uses. USL closed captioning systems currently only support cinema applications. However, they could be made to support live captioning through a software update. USL Products USL uses infrared transmission for all its accessibility products. IR transmission is ideal for many applications. The table below lists the USL accessibility products Model Number
Description
UPC-21
IR audio emitter. Single channel. Uses 95kHz transmission. Low cost.
UPC-28
Two-channel audio emitter. Uses 2.3MHz and 2.8MHz. Closed caption transmission option available.
IRH-501
Single-channel IR headphones. Uses 95kHz. Compatible with UPC-21.
IRH-701
Single-channel IR headphones. “Stethoscope” under chin style. Uses 95kHz. Compatible with UPC-21.
IRH-230
Two-channel IR headphones. Uses 2.3MHz and 2.8MHz. Compatible with UPC-28 when closed captioning not being used.
IRH-280
Two-channel IR headphones. Uses 2.3MHz and 2.8MHz. Compatible with UPC-28C IR emitter with closed captions.
CCH-100
Glasses type closed caption receiver. Removable electronics simplifies cleaning.
CCR-100
Closed caption receiver with a goose-neck mount.
Here to Serve USL has been serving the accessibility needs of cinema for nearly 30 years. We are ready to help ensure your church serves the widest possible audience. Please call us with your questions.
USL, Inc. 181 Bonetti Drive San Luis Obispo, CA 93401 U.S.A +1 805 549 0160 www.uslinc.com 6
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