262
D.L. Herzing
7.7 Processing and Decoding of the Informational
Content of Signals
We have not decoded potential modulated information in many of the
bands of frequenci~s in use by dolphins during social interaction. Dolphins
have the ability to independently modulate acoustic parameters of their
echolocation signals including click rate, frequency, and amplitude (Moore
and Pawloski 1990). Our abilities to decode this information may lead to a
better understanding of hearing abilities. Such modulation would likely be
found, and would be worthy of analysis, in communicative signals to conspecifics, including not only frequency-modulated whistles but the potentially rich source of information embedded in burst-pulsed vocalizations.
The mechanism by which such information is transmitted, shared, and
modified leads us to look for examples of teaching and how a developing
individual is guided and redirected toward appropriate modification of
signal use utilizing the constraints of communication and hearing.
Other potential techniques to apply to dolphin sound anaylsis include (1)
acoustic multiplexing (defined in human terms as the ability to hear conversations, background noise, and also carryon a conversation); (2) multimode imaging sonar (which does not use time-differential information but
rather spectral information as object moves in water, thereby analyzing
from the spectral signal itself); and (3) back-scatter illumination techniques
developed by Buckingham et al. (1996). Given the dolphins' noisy and
complex acoustic environment, these techniques would be useful to determine features of both dolphin hearing and communication. The larger issues
discussed by Bregman (1990) around the perception of an "auditory scene"
or unit of salient information should also be explored.
Other potential sources of subtle cues in the aquatic environment available to dolphins might include the reception of sound from molecular or
physical aspects of water manipulation, such as (1) the ability to create and
manipulate vortices (Marten et al. 1996), (2) the near-field effects of sound
and water molecules such as heat transfer via ensonification, low-frequency
particle motion, and pressure fluctuations (Turl 1993), or physical patterns
set up in water molecules as described in the physics of cymatics (Jenny
1974); and (3) interference patterns from return echoes theoretically
exploited for image processing by bats (Simmons et al. 1996). All hold
out interesting physical possibilities of information transfer and subtle
detection abilities yet unexplored.
7.8 Standarizing, Enhancing, and Synethesizing
Improved understanding about dolphin hearing and communication signal
detection and decoding can also be enhanced by the following:
D.L. Herzing
7.7 Processing and Decoding of the Informational
Content of Signals
We have not decoded potential modulated information in many of the
bands of frequenci~s in use by dolphins during social interaction. Dolphins
have the ability to independently modulate acoustic parameters of their
echolocation signals including click rate, frequency, and amplitude (Moore
and Pawloski 1990). Our abilities to decode this information may lead to a
better understanding of hearing abilities. Such modulation would likely be
found, and would be worthy of analysis, in communicative signals to conspecifics, including not only frequency-modulated whistles but the potentially rich source of information embedded in burst-pulsed vocalizations.
The mechanism by which such information is transmitted, shared, and
modified leads us to look for examples of teaching and how a developing
individual is guided and redirected toward appropriate modification of
signal use utilizing the constraints of communication and hearing.
Other potential techniques to apply to dolphin sound anaylsis include (1)
acoustic multiplexing (defined in human terms as the ability to hear conversations, background noise, and also carryon a conversation); (2) multimode imaging sonar (which does not use time-differential information but
rather spectral information as object moves in water, thereby analyzing
from the spectral signal itself); and (3) back-scatter illumination techniques
developed by Buckingham et al. (1996). Given the dolphins' noisy and
complex acoustic environment, these techniques would be useful to determine features of both dolphin hearing and communication. The larger issues
discussed by Bregman (1990) around the perception of an "auditory scene"
or unit of salient information should also be explored.
Other potential sources of subtle cues in the aquatic environment available to dolphins might include the reception of sound from molecular or
physical aspects of water manipulation, such as (1) the ability to create and
manipulate vortices (Marten et al. 1996), (2) the near-field effects of sound
and water molecules such as heat transfer via ensonification, low-frequency
particle motion, and pressure fluctuations (Turl 1993), or physical patterns
set up in water molecules as described in the physics of cymatics (Jenny
1974); and (3) interference patterns from return echoes theoretically
exploited for image processing by bats (Simmons et al. 1996). All hold
out interesting physical possibilities of information transfer and subtle
detection abilities yet unexplored.
7.8 Standarizing, Enhancing, and Synethesizing
Improved understanding about dolphin hearing and communication signal
detection and decoding can also be enhanced by the following: