Thanks a lot Richard that is very helpful.
C
--- In "Richard Ranft" <=
> wrote:
>
> Hi Chris, I'm afraid I don't have access to a PDF - the article is in
> copyright to Wiley and can be purchased from here:
> INFRASONIC COMPONENTS IN THE SONG OF THE CAPERCAILLIE TETRAO UROGALLUS
> http://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.1979.tb05021.x/abs=
tract
> Ibis Volume 121, Issue 1, pages 95-97, January 1979
>
> However, from memory, this bird emits true infrasound, i.e. components be=
low
> 20Hz, well below the cassowary example (although maybe this is just a cas=
e
> of needing better gear - the cassowary is a bigger beast and might be abl=
e
> to produce lower frequencies). The sound spreads into the audible range,=
> above 20Hz, which is what we humans hear. The best recordings of
> Capercaillie I've ever heard were made by Roger Boughton in Scotland, usi=
ng
> a Sennheiser MKH105 or MK110, a 'military' spec mike that can capture jus=
t a
> few Hz. With all respect to Klas, his recording just does not compare.
> Forget about using a parabola to record these birds properly: the lower t=
he
> frequency, the longer the wavelength, and by the simple physics of
> diffraction and reflection you can calculate that to capture 20Hz, the
> reflector needs to be at least 56 feet in diameter - instead use a decent=
> open mic and place it close up - takes many hours of fieldcraft but the
> results stand the test of time.
>
> Richard Ranft
> The British Library
> London
>
>
>
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