The Shepherd Centre is an early intervention program providing auditory habilitation for children with a hearing impairment. It was set up over 30 years ago at the initiative of Dr Bruce and his late wife Annette, after their two children were born profoundly deaf.
The centre provides services for children aged up to six years, encouraging them to acquire spoken language by developing listening and cognitive skills. This involves intensive one-on-one lessons in a play environment which follows the typical development of childhood. Most of the children will go on to attend mainstream schools, although some may attend a special needs school or a hearing support class attached to a mainstream school.
One of the key issues in developing education plans for each child is measuring their degree of hearing. However, this is difficult because the process used for older children and adults, in which they are asked to signify when they hear sounds, cannot be explained to a very young child.
The method that is used to test children between about seven months and three years of age is called Visual Reinforcement Orientation Audiometry. This involves teaching the child to turn their head when a special sound is heard, and reinforcing this by showing a moving toy or puppet in a lit-up window
Because the toy show is fun, most children will turn even if they hear the sounds only softly. By altering the frequency and intensity of the sounds, the staff can find out how much and how well the child can hear across a range of frequencies.
The cost involved in buying commercially-made boxes suitable for this method of testing was very high for a charity such as The Shepherd Centre, particularly as they needed more than one. According to Audiological Services Coordinator Jemini Patel, they also needed something that could be tailored to meet their exact requirements.
The centre therefore approached TAD to assist them. Volunteer Peter Hardy did the initial design of the electrical circuit required, and made a prototype. Marco Colli then took over and made the remaining two boxes.
Made from 6mm medium density fiberboard, the boxes have three 350mm square compartments stacked vertically, with a plinth at the bottom containing the electrical components. The testing is usually done in a darkened room, so the box is painted black to minimize its visibility.
On the front side of the side panels there is a slot into which slides a sheet of tinted perspex, which conceals the contents of the compartment from the child unless the internal light is on. The staff can remove this cover and change the toys when they think the child might be getting bored with the existing ones.
Each compartment contains a light and a power socket for plugging in the toy, which have to operate simultaneously so the toy starts moving as soon as the light comes on. These are activated by a