Geluid comfortable met 16KHz toonhoogte en 108dB pieptoon

[mosquito]

http://www.hse.gov.uk/research/crr_pdf/ ... r01343.pdf

An ultrasonic dog repeller was found to have a maximum output of 108 dB, 16 kHz at a distance
of 1.5 metres; this level decayed at the expected 6 dB per doubling of distance from the source.
The reaction of (human) observers ranged from no perception at any distance, to severe
discomfort in the ears about 12.5 metres away, in another room.