At 7m30s the video states that rolling noise (tires) starts being same/louder than propulsion noise at 30 kph. Reducing speeds from 50 kph to 30 kph reduces noi

At 7m30s the video states that rolling noise (tires) starts being same/louder than propulsion noise at 30 kph. Reducing speeds from 50 kph to 30 kph reduces noise by 6 dB (a change of 3 dB is halving/doubling). So yes, it's not surprising that 0-10/15 kph you hear the engine more.