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Delaware Assistive Technology Initiative

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Volume 11, Issue 3: Summer 2003

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What Is All This Talk
About Blue Teeth

Marvin Williams, AT Specialist, Kent County ATRC

Bluetooth is the newest kid on the technology block, and it holds a lot of promise for the assistive technology industry. Named for a 10th Century King of Denmark who unified the kingdoms of Denmark and Norway, Bluetooth is a short-range wireless communication specification that promises to improve and increase electronic access to a number of environments by overcoming some of the obstacles typical of current technology. Bluetooth technology will enable devices to communicate and transfer data wirelessly and without the line-of-site issues of infra red technology.

What does this mean for people
with disabilities?

In fact, the implications of the technology are staggering. Imagine a hearing impaired person going to a movie or a play and being able to hear the audio with improved clarity through her own Bluetooth hearing aid. Completely deaf individuals could use Bluetooth enabled viewers to watch movies, plays, or even sporting events with captions while actually at the event. Bluetooth devices would allow the users to be connected to the public address systems in places like theaters, airports, train stations, and arenas. A visually impaired person with a Bluetooth cell phone could trigger an audible-locating signal from an ATM, ticket counter, or informational kiosk. She could then use her phone or a Bluetooth headset to receive speech output of the information on the terminal's screen. Someone using a Bluetooth cell phone or headset could receive information about the busses at a certain bus stop, the names of streets and the direction the user is traveling, or whether a street is safe to cross. A person could enter a large office building and navigate the building's many floors and offices via audio announcements transmitted to a Bluetooth cell phone or headset.

So how does it work?

Bluetooth devices search each other out within their given operational range. Unlike devices that are wired together, Bluetooth devices do not have to be aware of the capabilities or properties of the devices to which they will connect beforehand. Bluetooth devices have a built-in mechanism that lets each device identify itself as well as its capabilities as it connects into this new Bluetooth network. This dynamic network does have a controlling device that designates itself as the master for the connection. Its programming and the capabilities necessary for the given task determine whether or not a device can be a master. For example, a cell phone may act as a master device when connecting to a headset, an ATM, or an informational kiosk. However, the same cell phone or headset may act as a slave device to the informational kiosk, now acting as the master device, broadcasting emergency evacuation information. The cell phone and kiosk can function in either capacity depending on the required function and their programming.

The master device broadcasts a signal requesting all slave or slave-capable devices to identify themselves. All possible slave devices that receive the signal send the master device information about what type of device it is and what its capabilities are. During this phase of communication, the slave device also sends the master device information necessary to synchronize and optimize their communication. Once the master collects the information from all of the available slaves, it selects the specific slave devices the user needs and begins selective communication with those devices only. It is this directed broadcast communication and directed receiving that prevents signal interference between various slave units. The master and slave can communicate as long as they stay within broadcast range of each other.

As Bluetooth operates on two power levels, it has two different ranges. The low power level has a maximum range of 20 feet, while the higher power range has a maximum range of 10 meters. By utilizing the two different power levels, larger Bluetooth networks can be easily established without overloading a single network. Thus, a student on a college campus would connect to the higher power Bluetooth broadcast for the building where her class is and connect to the lower powered network while she is in her class. That way, she does not listen to the lecture going on next door or three doors down.

So where do we stand currently?

Well, on the communications front, Bluetooth enabled phones are available on the market from most every cell phone manufacturer. This is because the majority of telecommunication industry experts agree that developments in Bluetooth will be cell phone driven. Of the 40 million Bluetooth chip sets produced last year, industry experts expect more than half to end up inside cell phones; and by 2005, 75% of cell phones are expected to be Bluetooth compatible.

Gn ReSound has developed the first Bluetooth cell phone headset specially designed for hearing aid wearers. It eliminates the need to remove the hearing aid in order to use the headset. Presently, a hearing-aid wearer has to remove the hearing aid to avoid the interference between the headset and the hearing aid.

GN ReSound’s specialized Bluetooth headset and how it’s wornGN ReSound’s specialized Bluetooth headset and how it’s worn

This new headset would fit over the ear with the hearing aid in place with virtually no risk of interference. This new headset weighs 28 grams and is compatible with some GN ReSound and Beltone hearing aids.

As Bluetooth technology spreads across the electronics landscape, the benefits for the disabled community will grow. Fortunately, the consumer electronics industry is recognizing the benefits of implementing universal design in developing new devices. Bluetooth definitely lends itself to universal design in consumer electronics. Industry is also beginning to address the needs of the disabled community with its products. While initially this was driven by the requirements of federal and state legislation, companies have begun to recognize that people with disabilities comprise a great untapped market that has money to spend on consumer electronics.

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