On Jan 23, 11:18 am, Magiel venema wrote:
....

Hi Magiel,

I am flying a exceptionally quiet helicopter which seems to be the
most silent helicopter made.
Eurocopter EC120. The noise level (overflight at Max. gross weight) is
78.7 dBA.
If somebody has other facts (e.g. helicopters with less noise), please
let me know.

martin

(We fly to the Matterhorn summit - http://www.lago-rundflug.de)