Vibrating signals

THE only system available to let hearing-impaired people know of an incoming call is the flash call system. Unfortunately, the system only works in one room and it only takes into account one alarm source, the phone. A new alarm system devised during a recent study conducted by the Centre for Telecommunications Studies in Paris, has just been developed to solve this problem.

The system, called a vibration to sensory system uses vibrations to communicate sound and alert the hearing impaired user. It has two main parts - an emitter and a receiver. The emitter has to be installed near the components under surveillance and connected to the appropriate alarms; such as the phone and the door bell. The ringing or beep is picked up by a microphone connected directly to the transmitter or by a system using the home's electric installation that transmit the data emitted at different spots in the home to the mike.

Once the volume and the pitch frequency of the sound sources are adjusted, the transmitter can send the information by radio to the receiver. Several transmitters equipped with different kinds of sensors can be scattered about the user's home. The receiver is a watch-band with an analogue watch, a radio receiver, a vibration generator and a control circuit that personalise the receiver and can pinpoint the origin of the alarm. A series of vibrations and light-emitting diodes tell the user which device is ringing. In this setup, the human body serves as the receiver's antenna.