|Residents of a duplex in Wacken, Schleswig-Holstein (North Germany) terrorised their neighbours for nights with the loud crowing of a rooster from an amplifier. According to police, a married couple plagued by inexplicable noise called police 4 times in one week. However, upon arrival of the officers the crowing from the adjacent dwelling had already stopped.
||When the officers were unable to contact the absent residents, they opened their door. In the bedroom they found sound-equipment with a time-switch and amplifier from which emanated every night between 2 and 4 a.m. the rooster-crowing at enormously high volume, directed at their neighbours' wall.|
The owner of that dwelling, 55, and his wife, 50, were charged with disturbance of the peace and bodily harm. (dpa) - Darmstaedter Echo
Only male fin whales sing loud songs
|These mammals need to call long-distance when it comes to attracting females
The low-frequency vocalisations of fin and blue whales are the most powerful and ubiquitous biological sounds in the ocean. Here we combine acoustic localisation and molecular techniques to show that, in fin whales, only males produce these vocalisations. This finding indicates that they may function as male breeding displays, and will help to focus concern on the impact of human-generated low-frequency sounds on recovering whale populations.
The long, patterned 15 - 30-Hz vocal sequences of fin whales (Balaenoptera physalus) can reach intensities of 184 - 186 decibels and can be detected throughout the world's oceans. However, the source of these vocalisations was hard to identify because of the inherent difficulty of studying wide-ranging pelagic species and in locating low-frequency sound sources in the ocean. Until now, their function was therefore unknown, making it difficult to assess the effects of increasing levels of human-produced sounds on these whales.
|Sound levels from commercial ships, military sonar, seismic surveys and ocean acoustic research are extremely high, and at least since the early 1960s, the amount of human-produced sound in the frequency range used by large whales has increased. A sound is detectable if its received level exceeds that of background noise by enough to be detected by the animal.|
An increase in ambient noise could thus reduce the distance over which receptive females might hear the vocalisations of males. To the extent that growth of Balaenoptera populations is limited by the encounter rate of receptive females with singing males, the recovery of fin- and blue-whale populations from past exploitation could be impeded by low-frequency sounds generated by human activity. - Excerpted from Nature (June 20, 2002)
|Deafness in whales?|
Yale researchers say tributylin oxide, a chemical used to keep barnacles off boats, may cause hearing loss in whales, reports Discover magazine. The toxin may damage the immune and hormone systems of other marine mammals as well. - The Globe and Mail
Hearing range of different animals compared with that of humans
During a Radio Netherlands interview in 2000, Dr. Kastelein of the Harderwijk Dolphinarium, stated the hearing range of several animal species for comparison as follows:
Humans: from about 20 Hz to 20 kHz; dolphins and bats: up to 140 kHz; dogs: up to 40 kHz; harbour porpoises: up to 180 kHz; seals and sea lions: up to 64 kHz; walrusses: like humans, plus infra-sound.
No noise is good noise!
Right to Quiet Society Newsletter, Spring 2005
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