The word "AVAS" is spelled as /ˈeɪvəz/ using the International Phonetic Alphabet. The first sound, /eɪ/, represents the diphthong vowel sound of "ay," which is a combination of the vowel sounds "eh" and "ee." The following sound, /v/, represents the voiced labiodental fricative consonant sound formed by placing the lower lip against the upper teeth and exhaling. Finally, the sound /z/ represents the voiced alveolar fricative consonant sound formed by vibrating the vocal cords while forcing air through a narrow gap between the tongue and the upper teeth.
AVAS stands for Acoustic Vehicle Alerting System. It is a safety feature installed in electric and hybrid vehicles to alert pedestrians and other vulnerable road users of the vehicle's presence. As these vehicles run quietly at low speeds, they often pose a risk to pedestrians, especially those with visual impairments who rely on their hearing to detect approaching vehicles.
The purpose of AVAS is to mitigate this risk by emitting a sound that replicates the noise produced by a traditional internal combustion engine vehicle, thus providing an acoustic warning of the approaching EV or hybrid. The sound is emitted from speakers located on the exterior of the vehicle and is activated when the vehicle is operating at low speeds or is reversing.
The specific characteristics and volume of the AVAS sound vary depending on regional regulations and manufacturer settings. Some systems generate a continuous tone, while others produce a pulsing or intermittent sound. The intention is to ensure the sound is distinct and recognizable as a moving vehicle.
By implementing AVAS, manufacturers aim to enhance the safety of electric and hybrid vehicles, reducing the chances of accidents involving pedestrians or other vulnerable road users. This technology helps maintain the harmony between conventional vehicles and their greener counterparts, enabling pedestrians to be alerted to the presence of quiet-running vehicles and supporting the goal of a sustainable transportation system.