[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: sounds - even more



     Most acoustic communication in both African and Asian elephants
consists of
very low frequency sounds, too low in pitch for people to perceive
easily (infrasonic).
These calls can have amplitudes as high as 117 dB SPL at 1 m, close to
the
threshold of discomfort in humans [Beranek, 1988]. Some of these calls
were first
described by Berg [1983]. However, she did not have the equipment to
accurately
record them and so described them as being of low amplitude. She neither
realized
the extent to which they dominated the elephants' acoustic repertoire
nor the role
these calls might play in long distance and inter-group communication.
Payne et al.
[1986] were the first to describe these calls as infrasonic and link
them to longdistance
communication.....
     Elephants make these calls in their larynx. The hyoid apparatus and
associated
laryngeal musculature of elephants differ from the basic mammalian
scheme in that
the hyoid structure has five rather than nine bones, and parts of these
bones are
joined loosely to the crania via muscles, tendons, and ligaments rather
than bones as
in most other mammals [Shoshani, 1998]. This allows for a greater
flexibility of the
larynx, which might aid in the production of infrasound. Interestingly,
Shoshani speculates
that this arrangement might have co-evolved as both a sound production
and a
cooling (!) mechanism, since this loose attachment of the larynx allows
the formation
of a pharyngeal pouch behind the tongue and above the epiglottis.
Elephants can
fill this pouch with water while they drink and have been observed to
insert their
trunk into their mouths, withdraw this water, and spray themselves with
it on hot
days or when far from a water source.
     Most infrasonic elephant calls have fundamental frequencies of
15-25 Hz
[Payne et al., 1986; Poole et al., 1988]. In this region of the acoustic
spectrum,
humans have poor but extant hearing. Therefore, a person standing
directly under
an elephant would be able to perceive almost all the calls that the
elephant makes.
In the field, this is neither practical nor safe, and there is typically
more than one
elephant in the vicinity-making proximity to all potential callers
impossible. From
personal experience and the reports of others [Poole, 1994], if you tape
record a
group of elephants in the wild and simultaneously write down all the
calls you
hear, you will find, upon later analysis of the tape, two to four times
more calls
than you had written. Thus, in practical terms, most of the acoustic
communication
of elephants is inaudible to humans.
     In contrast to humans, elephants have the best low-frequency
hearing of any
mammal yet tested [Heffner and Heffner, 1982], with hearing in the low
frequencies
10-100 times better than that of humans. The hearing of elephants needs
to be explored
further, for these psychoacoustic data are from just one adolescent
Asian elephant.
Although no audiogram has been constructed for the African elephant,
other
evidence suggests that they have low-frequency hearing comparable to
Asian elephants.
For example, two current and three extinct taxa (Loxodonta; Elephas,
Mammut, Mammuthus, and gomphotheres) share anatomical structures that
should
aid in the perception or localization of low-frequency sound. These
include "large
interaural distance; large ear drums; bulky ossicles; wide basilar
membranes, diminished
outer lamina, and thing, spongy inner lamina . . . that is more
flexible, thus
consistent with resonances of [infrasound]" [Meng et al., 1997].

W.R. Langbauer, Jr. 2000. Elephant Communication. Zoo Biology 19:425-445


Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/
Chief Preparator
Department of Earth Sciences
Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
 
Phone: 303-370-6392
Fax: 303-331-6492
************************************************************
for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 
https://scientists.dmns.org/sites/kencarpenter/default.aspx

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of Ken.Carpenter@dmns.org
Sent: Monday, February 20, 2006 2:35 PM
To: simkoning@msn.com; dinosaur@usc.edu
Subject: sounds

 There is no strong consensus on the vocal repertoire of the African
elephant in general, and no consensus on the number of rumble subtypes
in particular. Rumbles are frequency-modulated, harmonically rich
vocalizations with frequency components near or within the infrasonic
range. In an early study, Berg (1983) classified 209 vocalizations from
nine captive elephants into 10 acoustic types, including two separate
types of rumble (the 'growl' and 'rolling growl' in Berg's terminology).
In the parameters described, however, the two rumbles differ very
little, or not at all. Mean durations do differ but they overlap
extensively, and the range of fundamental frequencies are the same for
the two calls. Among wild elephants, Poole et al. (1988) categorized
seven rumble types according to their social function, and provided
various acoustic characteristics (e.g. frequency contour
characteristics) for exemplars corresponding to each type. Poole (1999)
also characterized oestrous rumbles according to measures of the
fundamental contour. From these descriptions, however, it is not
possible to determine whether these rumble types differ acoustically as
discrete subtypes or in a graded manner.

JOSEPH SOLTIS, KIRSTEN LEONG & ANNE SAVAGE African elephant vocal
communication II: rumble variation reflects the individual identity and
emotional state of callers. ANIMAL BEHAVIOUR, 2005, 70, 589-599



Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology/ Chief Preparator Department of
Earth Sciences Denver Museum of Nature & Science
2001 Colorado Blvd.
Denver, CO 80205
 
Phone: 303-370-6392
Fax: 303-331-6492
************************************************************
for PDFs of some of my publications, as well as information of the Cedar
Mountain Project: 
https://scientists.dmns.org/sites/kencarpenter/default.aspx

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of Sim Koning
Sent: Monday, February 20, 2006 12:49 PM
To: dinosaur@usc.edu
Subject: RE: Guanlong wucaii (was RE: Early Version of T. Rex Is
Discovered)

I always thought it was same with Parasauroplophus. I thought the idea
was that sound was generated by the vocal cords and then resonated
through the crest like a brass instrument. I'm pretty sure elephants do
the same with their trunks to create very low frequency sounds. Elephant
seals don't raise their proboscis, its inflated and drops down in front
of the mouth. The nose acts as a resonating chamber that cane generate
very load roars that can heard for miles.


>From: Ken.Carpenter@dmns.org
>Reply-To: Ken.Carpenter@dmns.org
>To: simkoning@msn.com, dinosaur@usc.edu
>Subject: RE: Guanlong wucaii (was RE: Early Version of T. Rex Is
>Discovered)
>Date: Mon, 20 Feb 2006 11:30:00 -0700
>
>It is through their vocal chords. They lift their proboscis, which 
>makes you think it is through the nose.
>
>
>Kenneth Carpenter, Ph.D.
>Curator of Lower Vertebrate Paleontology/ Chief Preparator Department 
>of Earth Sciences Denver Museum of Nature & Science
>2001 Colorado Blvd.
>Denver, CO 80205
>
>Phone: 303-370-6392
>Fax: 303-331-6492
>************************************************************
>for PDFs of some of my publications, as well as information of the 
>Cedar Mountain Project:
>https://scientists.dmns.org/sites/kencarpenter/default.aspx
>
>-----Original Message-----
>From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf 
>Of Sim Koning
>Sent: Monday, February 20, 2006 11:25 AM
>To: dinosaur@usc.edu
>Subject: RE: Guanlong wucaii (was RE: Early Version of T. Rex Is
>Discovered)
>
>"since when do animals make bellowing noises through their nose"
>
>Elephant seals and elephants do.
>
>
> >From: Ken.Carpenter@dmns.org
> >Reply-To: Ken.Carpenter@dmns.org
> >To: blackphoenix@eastlink.ca, dinosaur@usc.edu
> >Subject: RE: Guanlong wucaii (was RE: Early Version of T. Rex Is
> >Discovered)
> >Date: Thu, 09 Feb 2006 13:28:38 -0700
> >
> >You took my comment waaaaaaaay to serious. I was making fun of the 
> >resonanting chamber hypothesis of lamberosaurs (since when do animals

> >make bellowing noises through their nose????) AND Jack Horner's 
> >scavenging hypothesis.
> >
> >
> >Kenneth Carpenter, Ph.D.
> >Curator of Lower Vertebrate Paleontology/ Chief Preparator Department

> >of Earth Sciences Denver Museum of Nature & Science
> >2001 Colorado Blvd.
> >Denver, CO 80205
> >
> >Phone: 303-370-6392
> >Fax: 303-331-6492
> >************************************************************
> >for PDFs of some of my publications, as well as information of the 
> >Cedar Mountain Project:
> >https://scientists.dmns.org/sites/kencarpenter/default.aspx
> >
> >-----Original Message-----
> >From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On 
> >Behalf Of Amtoine Grant
> >Sent: Thursday, February 09, 2006 12:50 PM
> >To: dinosaur@usc.edu
> >Subject: Re: Guanlong wucaii (was RE: Early Version of T. Rex Is
> >Discovered)
> >
> >On Thursday, February 9, 2006, at 01:05  PM, Ken.Carpenter@dmns.org
> >wrote:
> >
> > > The crest obviously is a resonating chamber like lambeosaurs to 
> > > call
>
> > > other scavengers to dinner - ;-)
> >
> >
> >Seemingly illogical given that that would only mean less food for the

> >'calling' individual. Vultures & bald eagles, for example, don't 
> >summon
>
> >each other AND they often squabble and/or fight . HOWEVER, it would 
> >make sense if that when groups were assembled they would cooperate in

> >defense of themselves & the carcass from the [at that time larger 
> >representatives of] other predaceous theropods of the time. This 
> >would also be a good starting point for the socialization that 
> >certain assemblages of tyrannosaurid fossils represent. Besides the 
> >obvious social implications of a head-borne crest that works directly

> >against predation. . .
>
>