5. Acoustics and Social Behavior
243
frequencies are found in fear, arousal, and alerting contexts. Sounds with
discrete time features, stretching broadband frequency widths, are found in
a variety of contexts including excitement, feeding, and aggressive displays.
Finally, longer vocalizations, modulated by frequency, are found in contact,
display, and reunion contexts. Until both the terminology of vocalizations
and their spectral information is made consistent and the full bandwidth
of social vocalizations if obtained, these should be considered preliminary
observations. The evolution of acoustic communication signals shows
conservation in features and should be looked at in delphinids.
The universal features of both intra- and interspecies communication is
a potential field of investigation. Morton (1977) has attempted to define
the motivational and structural rules for birds and mammals. McConnel
(1990) reported the cross-cultural mapping of acoustic signals and affective
states in humans during communicative interactions with dogs, indicating the emergence of convergent processes of signal use. Evidence for
feature conservation of affective states in human infant communication
(Hauser 1996) and cross-cultural signals (Clynes 1977) have been noted,
indicating that similar perceptual strategies, as far as phonetic boundaries,
may be the rule not the exception. Strategies of categorizing along
an acoustic continuum may be an ancient evolutionary mechanism and
categories may evolve independently but consistently due to physiological
mechanisms.
3.10 Social Acoustics
While psychoacoustics may be well understood (Nachtigall et aI., Chapter
8), social acoustics, "the cultural encoding of information heard and its
meaning," is not. The detection of conspecific fighting at a distance may
include the following: broad and subtle messages, including the types of
sounds associated with a particular behavior (i.e., squawks during fighting,
or the subtle escalation and rate of such sounds in a sequence of activity);
and general information about individuals engaged in the behavior; their
geographical location, gender, or behavioral messages such as predicted
outcomes from a confrontation by changes in loudness of a sound, rates of
sounds, and silent periods. The potential combination of information such
as hearing the squawks of a known individual, conspecific replies, the escalation of rates or intensities of vocalizations, and participation by other
identifiable conspecifics might be information a receiver could potentially
hear and use. This may yield decision-making information (coming to the
aid or fleeing a situation) based on social status or physical abilities of the
individual receiver. Spatio-temporal features may be preserved, including
both the merger of time-dependent (relative spacing of signals in time)
and time-independent (grammatical order and rules) cues, preserving
the sequence, rhythms, time, bouts, intensity of rate or signals, and
grammarical rules of communication.
243
frequencies are found in fear, arousal, and alerting contexts. Sounds with
discrete time features, stretching broadband frequency widths, are found in
a variety of contexts including excitement, feeding, and aggressive displays.
Finally, longer vocalizations, modulated by frequency, are found in contact,
display, and reunion contexts. Until both the terminology of vocalizations
and their spectral information is made consistent and the full bandwidth
of social vocalizations if obtained, these should be considered preliminary
observations. The evolution of acoustic communication signals shows
conservation in features and should be looked at in delphinids.
The universal features of both intra- and interspecies communication is
a potential field of investigation. Morton (1977) has attempted to define
the motivational and structural rules for birds and mammals. McConnel
(1990) reported the cross-cultural mapping of acoustic signals and affective
states in humans during communicative interactions with dogs, indicating the emergence of convergent processes of signal use. Evidence for
feature conservation of affective states in human infant communication
(Hauser 1996) and cross-cultural signals (Clynes 1977) have been noted,
indicating that similar perceptual strategies, as far as phonetic boundaries,
may be the rule not the exception. Strategies of categorizing along
an acoustic continuum may be an ancient evolutionary mechanism and
categories may evolve independently but consistently due to physiological
mechanisms.
3.10 Social Acoustics
While psychoacoustics may be well understood (Nachtigall et aI., Chapter
8), social acoustics, "the cultural encoding of information heard and its
meaning," is not. The detection of conspecific fighting at a distance may
include the following: broad and subtle messages, including the types of
sounds associated with a particular behavior (i.e., squawks during fighting,
or the subtle escalation and rate of such sounds in a sequence of activity);
and general information about individuals engaged in the behavior; their
geographical location, gender, or behavioral messages such as predicted
outcomes from a confrontation by changes in loudness of a sound, rates of
sounds, and silent periods. The potential combination of information such
as hearing the squawks of a known individual, conspecific replies, the escalation of rates or intensities of vocalizations, and participation by other
identifiable conspecifics might be information a receiver could potentially
hear and use. This may yield decision-making information (coming to the
aid or fleeing a situation) based on social status or physical abilities of the
individual receiver. Spatio-temporal features may be preserved, including
both the merger of time-dependent (relative spacing of signals in time)
and time-independent (grammatical order and rules) cues, preserving
the sequence, rhythms, time, bouts, intensity of rate or signals, and
grammarical rules of communication.