A duck quack fits the bill as a less stressful alternative to car horns, scientists have found.

Researchers at Soongsil University in Seoul, South Korea, tested variations of the classic “ah-oo-gah” horn on 100 volunteers before settling on the quack as most pedestrian friendly.

“Our klaxon can immediately alert the pedestrians of the danger while also reducing the unpleasantness and stress of the sound,” lead researcher Professor Myung-Jin Bae said, according to Sky News.

Researchers looked at the development of the car horn since it was introduced in 1908 and found that the quack could increase safety by being less startling to pedestrians and less distracting to drivers.