Overview
- At the ASA–ASJ meeting in Honolulu (Dec 1–5), a Japan-led team reported that signals dominated by low frequencies were rated most detectable.
- The group built a library of approach sounds using onomatopoeic cues combined with 1/f (pink) noise and tested them in both lab and real street settings.
- Participants ranked each sound for detectability, perceived urgency and pleasantness, with a high–pink-noise variant emerging as the top performer.
- The researchers attribute the result to reduced masking, as low-frequency energy cuts through common ambient sounds more reliably than higher tones.
- Findings could inform Acoustic Vehicle Alerting Systems, which are mandated at low speeds in many countries, and the team plans to extend testing to e-bikes and e-scooters.