Temporal integration of partial loudness of helicopter-like sounds

When developing new vehicles that are to be operated in existing background noise, such as electric vertical take-off and landing aircraft (eVTOLs) cities, a sound design goal should minimize the loudness given noise. Rotorcraft sounds characterised by their pulses, choice of rotor size number allows vary temporal characteristics. We asked participants compare pulse trains with durations 1, 2, 5, 10 20 ms rate Hz two-interval, two-alternatives forced task 1-up/1-down procedure. Street noise was presented simultaneously trains, had same root-mean-square (RMS) level fixed reference train about 65 dB SPL. First results indicate short duration need considerably less RMS result long duration, i.e. partial shorter pulses is higher at equivalent pressure level.