yes, low frequency sounds extending into the infra sounds realm are
considered anthropogenic noise, and thus they are a component of the
anthropophony. Ship traffic is the main source and produce the masking of
large marine mammals signals.
Concerning infra sounds and the debate about the boundaries of the concept
of "sound" it is important to say that human beings (and animals too) are
sensitive to infra sounds even if not perceived with ears. The perception
of infra sounds can be "physical" with the whole body or with a partial
perception through ears and often this type of low frequencies produces
discomfort. Often the receiver is not aware of what is happening, he only
feels bad (e.g. nausea). This sometimes happen close to wind farms, but
very few studies focus on infra sounds and the beats of multiple infrasound
sources. I recently attended a conference session on the measure of wind
farm noises (on land, not marine) and all studies presented were made with
phonometers with the "A" weighting curve. Some hearing test were made with
headphones, completely forgetting the ability to perceive infra sounds with
the body.
Gianni
2014-06-29 0:54 GMT+02:00 [naturerecordists] <
>:
>
>
> > it is also important to consider that "sound" is usually considered wha=
t
> > humans can hear, thus limiting the frequencies of sound to say 50 to
> > 16000Hz and naming infra- and ultra- sounds the frequencies beyond thos=
e
> > limits. However, as biologists, we also can consider "sound" all acoust=
ic
> > events that can be received and perceived by a living being.
>
> Gianni,
>
> There is concern that infrasound from ships may be disturbing the long
> distance communications of whales across hundreds of miles of ocean. Thes=
e
> low frequency sounds cannot be heard by the human ear, but are they not
> still anthropophony?
>
> BTW, I can hear down to around 5Hz. Does that make me a whale? :-)
>
> David Brinicombe
>
>
>
--
Centro Interdisciplinare di Bioacustica e Ricerche Ambientali
Universit=C3=A0 degli Studi di Pavia
Via Taramelli 24, 27100 Pavia
http://www.unipv.it/cibra
http://mammiferimarini.unipv.it
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