Talking Blues: a portable augmentative communications device

by Marc Krizack (krizack@sfsu.edu)
 

High tech assistive devices are often large and unwieldy, making the user conspicuous and sometimes overly self-conscious.  Yet some high tech solutions can be simple, small,  and totally cool.  Such is the case with a  portable augmentative communications device (APCD) designed to be sewn into a blue jeans jacket or vest.

The device, developed at the University of North Carolina at Chapel Hill School of Medicine, is designed for people who cannot speak intelligibly.  It is essentially a vest with voice recording and playback capabilities.  It was designed to be easy to activate and portable, two features that usually do not coincide in similar commercial devices.   The prototype was designed for a 15-year old boy with cerebral palsy, who had both a speech impediment and difficulties with fine motor control.

Concealed messages
The idea behind the vest is that a person with intelligible speech can record four separate messages which the wearer of the vest can manually activate when necessary.  One of the design challenges was to come up with activation pads that would be easy to use yet not so sensitive as to be activated by usual movements.  The pads, wires and circuitry had to  be sewn into the vest so that they would be protected from exposure to the outside world, where they could be damaged by accident or weather, and from exposure to the wearer, who might be injured or made uncomfortable.  Other important considerations were ease of use, adequate length of the recordings and an accessible battery compartment.

The undertaking by two researchers in the UNC School of Medicine's department of Biochemical Engineering also required taking into account a variety of practical lifestyle questions.  The vest needed to be both lightweight and durable and be able to incorporate the electronic circuitry for both recording and playback.  The device needed to be removable so the vest could be washed and the device and its circuitry needed to be hidden from view so that the vest would look no different from other vests.

User's choice of activation technique
The APCD includes a jeans vest, four activation pads, a speaker, and a box containing the circuitry and a 9V battery. It is a modular design that allows all the components to be removed, interchanged, or replaced.  The vest was purchased at a thrift store and then modified by a tailor. Activation of four prerecorded messages is possible through four different activation areas on the vest. These activation areas are custom designed switches about 2 inches by 1 inch in size, that allow pull or press activation for ease of use. The pull actuators are key chains, however any object of the user's choice can replace the key chains.  It is also possible to remove the key chains and activate the switches simply by pushing on the activation area.

The battery-powered voice recorder and player unit is located in a control box which is enclosed into a special pocket sewn on the upper back of the vest, directly below the collar.  The control circuitry is enclosed in a modified commercial polystyrene box.  In addition to housing the circuitry, the box also contains a 9V battery, a microphone, a record switch, an LED indicator, activation pad connector plugs, speaker connector plug, RS232C serial port, and an ON/OFF switch. The battery compartment is isolated from the main circuitry and is accessible through a latch that is held in place by a single screw.

Cost
The  total cost of the APCD was around US$100, which the inventors feel is fairly reasonable, especially when compared to other communication devices on the market which can cost many times more.  The 9V battery was determined to last approximately two weeks with normal usage, which was deemed to be acceptable power consumption.  The 15-year old boy was still using the jacket and APCD six months later.

For more information about the talking vest, contact Jeremy Cummings at jeremyc@bme.unc.edu