They are really surprisingly not loud. Not silent either, but not annoyingly, or disturbingly loud. Not comparable to the much, much older Bell UH-1 which we called 'Teppichklopfer' (carpet banger?). So it seems they know something about making helos less noisy.
I say this from the experience of having seen them come down maybe 200 times in the last 15 years? Sometimes just practicing it seems, with inner city, suburban, or park and field background noise floor.
[1] https://en.wikipedia.org/wiki/Eurocopter_EC135
They are really surprisingly not loud. Not silent either, but not annoyingly, or disturbingly loud. Not comparable to the much, much older Bell UH-1 which we called 'Teppichklopfer' (carpet banger?). So it seems they know something about making helos less noisy.
I say this from the experience of having seen them come down maybe 200 times in the last 15 years? Sometimes just practicing it seems, with inner city, suburban, or park and field background noise floor.