Charles Brown

• Ph.D.
• University of South Alabama

This is an uncorrected proof.

Many mammalian acoustic displays are generated by vibrations of the vocal folds. The cardinal acoustic index of-cal parameters that determine fundamental frequency is critical for an accurate analysis of acoustic communication systems. Though the relationship between F0 and body size is well established in some vertebrate taxa (anura for example),...

The incidence of collisions between motorcyclists and other vehicles may be significantly reduced by research that improves the acoustic awareness of cyclists, and thus heightens the ability of cyclists to respond to unexpected incursions from the surrounding traffic. We use our hearing as an early warning system, and hearing swiftly redirects our...

The sections in this article are:

Hearing is a function of the acoustic signal and the properties of the environment that structure the sound. To better understand how hearing is affected by structural properties, the current research investigated the impact of football helmets for hearing. Speech signals were broadcast at three angles of incidence (0°, 45°, or 90°) to an artificia...

The acuity of acoustically evoked orientation was studied in great horned owls and red-tailed hawks to recordings of passerine alarm and mobbing calls. Video taped records of the orientation response of captive birds under semi-naturalistic conditions revealed that the localization of hawk alarm calls was inaccurate and the call appeared to activel...

and Summary Sound propagation measurements and background noise measurements were conducted to assess the optimal frequency of sounds for long‐range vocal communication in thirteenlined ground squirrels ( Spermophilus tridecemlineatus ). The results show that when the source and receiver are elevated above the ground 18 cm and 6 cm respectively (el...

Recent studies have revealed that in some ground squirrel species alarm calling behavior is most prevalent among individuals with nearby genetic relatives. A playback experiment was conducted to determine if the predator-elicited vocalization of the thirteen-lined ground squirrel, Spermophilus tridecemlineatus, is capable of evoking escape or watch...

Current Topics in Primate Vocal Communication. Elke Zimmermann. John D. Newman. and Uwe Jürgens. eds. New York: Plenum Press, 1995. 286 pp.

Computers are often used to simulate real world activities and events. The usefulness of a software simulation is determined by the validity of the underlying model of the system. Software simulation often treats the real world in a less random and more predictable fashion than is the case in nature. The use of an actual physical controlled object...

Most neurobiological and behavioral studies of the perception of species-specific vocalizations reflect in their design two assumptions. First, it is usually assumed that primate vocal production mirrors the idealized case for speech. That is, coupled synchronous oscillations of the vocal folds, similar to those underlying the production of vowels...

Humans and monkeys were compared in their identification of phoneme boundaries along synthetic stop-glide continua in syllable-initial /bo/-/wa/ or syllable-final /bab/-/baw/ contrasts differing in overall syllable duration. For both contrasts, humans were first tested with a conventional written identification procedure. Here, similar phoneme boun...

Multidimensional scaling (MDS) was used to compare perceptual maps for 10 synthetic English vowels in humans and Old World monkeys (Macaca fuscata and Cercopithecus albogularis). Subjects discriminated among the vowels using a repeating background procedure, and reaction times were submitted to an MDS analysis to derive measures of perceive similar...

Multidimensional scaling (MDS) was used to compare perceptual maps for 10 synthetic English vowels in humans and Old World monkeys (Macaca fuscata andCercopithecus albogularis). Subjects discriminated among the vowels using a repeating background procedure, and reaction times were submitted to an MDS analysis to derive measures of perceived similar...

Human and monkey perception of the American English liquid /ra-la/ contrast was compared using various synthetic continua in which the normal spectral and temporal cues were higher either complete, partial, or altered in various ways. Two experiments compared human and monkey discrimination of the various continua using a low-uncertainty repeating-...

Humans and monkeys were compared in their perception of phoneme boundary shifts along two synthetic stop‐glide /bα‐wα/ continua differing in overall syllable duration (150 vs 320 ms). Humans were first tested with a written identification procedure and showed a boundary shift to longer transition durations with increased syllable duration, as previ...

Acoustic and laryngographic measurements of Sykes's monkey (Cercopithecus albogularis) squeals showed that acoustic variation between exemplars was principally due to 4 underlying modes of modification: (Class I) variation in the transfer function produced by articulation, (Class II) variation in F0 produced by inflection, (Class III) variation in...

Four Sykes's monkeys (Cercopithecus albogularis) and 4 humans (Homo sapiens) discriminated among 12 chirps presented in a repeating background paradigm. The test stimuli consisted of sets of 4 chirps recorded from Sykes's monkeys, red-tailed monkeys (C. ascanius), and small East African birds. Reaction times were submitted to a multidimensional sca...

Four Sykes's monkeys (Cercopithecus albogularis) and 4 humans (Homo sapiens) discriminated among 12 chirps presented in a repeating background paradigm. The test stimuli consisted of sets of 4 chirps recorded from Sykes's monkeys, red-tailed monkeys (C. ascanius), and small East African birds. Reaction times were submitted to a multidimensional sca...

The ongoing acoustic ambience of all terrestrial habitats is a reflection of the sum of the biotic sources of sound in the environment (e.g., vocalizations, insect wing noise, and the staccato hammering of woodpeckers) and the non-biotic sources of sound (e.g., wind- and rain-induced vegetation movement and thunder). Different habitats are apt to s...

Four Sykes’ monkeys (Cercopithecus albogularis) and three humans discriminated among 12 chirps presented in a repeating background paradigm. The test stimuli consisted of sets of four chirps recorded from Sykes’ monkeys, red‐tailed monkeys (Ce. ascanius), and small East African birds, respectively. Reaction times were submitted to a multidimensiona...

This study examined the effects of presenting various signal and noise levels on pure-tone frequency difference limens (FDLs) in humans and monkey. Signal levels for two frequencies of 500 Hz and 4 kHz were varied both in quiet and in noise. For the lower frequency of 500 Hz, the two species exhibited qualitatively divergent FDLs as level increased...

This study examined the effects of varying signal duration and pulse repetition rate on pure tone frequency difference limens (FDLs) at 500 Hz and 4 kHz in humans and monkeys. Two experiments examined FDLs as a function of tone duration from 12-400 ms, using stimuli presented either with a constant pulse rate, or with a constant interstimulus inter...

Simultaneous acoustic and laryngographic recordings were made of 176 blue monkey (Cercopithecus mitis) vocalizations. Four classes of periodic vocalizations were identified. In class I calls the rate of phonation ranged from 547 to 1211 Hz. The acoustic output of class I calls was harmonically related to the rate of phonation and ranged from approx...

Frequency (delta F) and intensity (delta I) difference limens were directly compared in Mongolian gerbils (Meriones unguiculatus), Old World African Monkeys (Cercopithecus mitis, Cercocebus albigena), and humans. Methods employed a repeating background AX discrimination procedure, and positive (food) reinforcement for animals. For delta I, there we...

The audible distance of 11 primate vocalizations uttered by blue monkeys, Cercopithecus mitis, and grey-cheeked mangabeys, Cercocebus albigena, and the human utterance ‘hey’ were determined experimentally. Calculations were based on measurements of (1) sound power of vocal signals (Brown: Bioacoustics, in press), (2) the attenuation rates of sound...

The substitution method was adopted from industrial acoustics (Francois and de Montussaint 1972) to “eliminate the influence of the environment” on measurements of the amplitude of vocalizations given by blue monkeysCercopithecus mitis and grey-cheeked mangabeysCercocebus albigena. Measurements were conducted of sound power and sound pressure level...

Changes in auditory sensitivity as a function of signal duration were studied in two species of Old World monkeys. Testing was conducted under free-field conditions with pure tones 250, 800, 1600, and 4000 Hz in frequency. Test stimuli ranged in duration from 35-2000 ms. The results showed that the temporal integration functions for the blue monkey...

Old World forest primates may need to signal vocally over long distances in noisy habitats. Perceptual experiments focused on the audibility of signals in noise were conducted in the laboratory using standard psychoacoustical methods. Six human listeners, two blue monkeys (Cercopithecus mitis), and two grey-cheeked mangabeys (Cercocebus albigena) s...

The loss of the ability to localize sounds was discovered to occur in rats as a consequence of aging. Subjects were trained in a two-alternative forced-choice paradigm to press the left bar if a sound was presented from the left side and to press the right bar if sound was presented from the right side. Testing was conducted with a brief 200 msec p...

B-wave increment threshold experiments in the rat show that "rod saturation" occurs at different background levels with different anesthetics. Rod saturation builds up over the first 60 sec of light adaptation in pentobarbital anesthetized but not in urethane anesthetized animals. These and other findings suggest that "rod saturation" can occur whe...

Intrasexual conflict and mating behavior were observed in a population of thirteen-lined ground squirrels (Spermophilus tridecemlineatus). Success in male-male competition was related strongly to male weight, whereas both the weight and age of males were correlated positively with estimated mating success.Between-season fluctuations in the density...

Minimum audible angles for localization in the vertical and horizontal planes were psychophysically determined in Old World monkeys (Macaca). In the vertical condition the test stimuli consisted of primate vocalizations and bands of noise. Minimum audible angles ranged from 3 degrees to greater than 20 degrees for signals of various bandwidths. The...

The acuity of auditory localization in Old World monkeys (Macaca) was determined psychophysically for 44 noise bands graded in bandwidth and center frequency. The acuity of localization was assessed through the method of constant stimuli under free-field conditions in an anechoic chamber. Monkeys were trained through positive-reinforcement operant-...

The acuity of auditory localization in Old World monkeys (M a c a c a) was determined psychophysically for 44 noise bands graded in bandwidth and center frequency. The acuity of localization was assessed through the method of constant stimuli under free‐field conditions in an anechoic chamber. Monkeys were trained through positive‐reinforcement ope...

The ability of 3 monkeys ( Macaca nemestrina and M. mulatta) to resolve the spatial origin of monkey vocalizations was psychophysically determined. Ss were trained through positive reinforcement operant conditioning procedures to report the detection of a change in the horizontal coordinate (azimuth) of the signal's location. Each S was tested wit...

Monkeys (Macaca) were trained by operant conditioning techniques to report the minimum detectable change in location of a sound in space, and were tested with a series of recorded coo or clear call vocalizations. Acuity of localization varied from approximately 4 degrees to 15 degrees and was a function of the magnitude of the change in pitch (freq...

The acuity of auditory localization in Old World monkeys (Macaca) was psychophysically determined for nine sinusoidal stimuli ranging from 250 Hz to 16 kHz. Monkeys were trained through positive reinforcement operant conditioning procedures to contact a response disk (observing response) initiating a repetitive series of 300-ms pure tones presented...

The acuity of directional hearing in Old World monkeys (Macaca) was assessed psychophysically through positive reinforcement operant conditioning procedures. The monkey's observing response, contact with the response disk, initiated a train of acoustic stimuli presented from the standard location, 0° azimuth. Intermittently the location of the stim...

The ability of monkeys (Macaca) to detect a change in the location of a sound in space was psychophysically assessed through the employment of operant‐conditioning techniques. Contact with a response disk initiated a train of acoustic stimuli pulsed from a standard location (0° azimuth). Following a variable number of pulses the stimulus changed it...

Monkeys (Macaca) were trained by operant conditioning techniques to report the minimum discriminable change in the locus of a sound in space. When a monkey made contact with the response key, a pulsed acoustic stimulus was presented from a standard location (zero degrees azimuth). After a variable number of pulses the stimulus changed position from...

Three generalization procedures were used to investigate inhibitory stimulus control following discrimination learning with few errors. Three groups of pigeons acquired a discrimination between a green stimulus (the positive stimulus) and a vertical or horizontal line (the negative stimulus) through differential autoshaping followed by multiple sch...

Pigeons initially trained on a simultaneous discrimination of line orientation (S1) were subsequently transferred to a wavelength discrimination (S2). Three transfer procedures were employed. The abrupt-transfer Ss were “abruptly” switched from S1 to the S2 dimension. The stimulus-compounding Ss were trained on a compound stimulus consisting of S1...

Hearing is a function of the acoustic signal and the properties of the environment that structure the sound. To better understand how hearing is affected by structural properties, the current research investigated the impact of football helmets for hearing. Speech signals were broadcast at three angles of incidence (0°, 45°, or 90°) to an artificia...

argues that our incomplete understanding of the perception of complex speech sounds stems from a failure to adequately address the biology of language examines the vocal repertoires, auditory sensitivities, and acoustic ecologies of Old World monkeys findings are consistent with the idea that the form of complex vocal signals—and the perceptual...

Thesis (Ph. D.)--Michigan State University. Dept. of Psychology, 1976. Includes bibliographical references (leaves 164-168). Microfilm. s

Thesis (M.A.)--Michigan State University. Dept. of Psychology, 1973. Includes bibliographical references (leaves 27-28).

Thesis (Ph. D.)--Michigan State University. Dept. of Psychology, 1976. Includes bibliographical references (leaves 164-168).