Acoustic traffic signal for blind pedestrians

✍ Scribed by Torben Poulsen

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 673 KB
• Volume: 15
• Category: Article
• ISSN: 0003-682X
• DOI: 10.1016/0003-682x(82)90025-1

✦ Synopsis

The development of an acoustic traffic signal for blind pedestrians is described. The WAL K and WAITsignals used represent a compromise between many contradictory demands, e.g. easy localisation and detection in a background of traffic noise, minimum annoyance, maximum attenuation into dwellings and simple and reliable construction. The WALK sound consists of 200ms pulses at a repetition rate of 2"5 Hz. The WA ITsound consists of 400 ms pulses at a repetition rate of O'5 Hz. Both WALK and WA ITpulses are formed from an 880 Hz sawtooth or square wave signal.

A weak attention signal is audible (automatic level control) within a distance of 2-3 m from the traffic light pole. The system has been in use for more than 2 years. Twenty-six blind pedestrians tested the system and found it very useful. A questionnaire investigation showed no adverse reactions from neighbours to the system. The attention system is being standardised in Denmark. The system is prepared for extension with a louder guiding signal which guides the blind across the crossing.