A simple device for the preparation of exactly aligned dichotic tapes

A system is described involving three tape recorders and a control device whereby dichotic tapes can be prepared with onset alignment accurate to a few milliseconds, or to a measured asynchrony if required. No modifications of any sort are necessary for the three tape recorders. The two channels are separately recorded in the speaker’s own time, the only requirement being that the separate words be spoken with an interword interval of 350 msec or more, to provide sufficient time for starting and stopping the system. A tone burst is placed directly on tape on another channel ahead of each word, the latter being delayed by recording in tandem through two tape recorders. The first recorder is set to the delay (echo, NAB) facility, while the tone is recorded directly on the second. Subsequently, when this is done for each item on the two speech channels, the device, described below. utilizes the tone bursts to align the two input recorders. It then rerecords each pair of words on to the third (output or dichotic) machine, to the desired synchrony/asynchrony, and interitem interval. The system can be left to align the two channels automatically. A maximum repetition rate of two dichotic pairs every 1.3 sec can be achieved with Revox A77 tape recorders.     

Perceiving the numerosity of rapidly occurring auditory events in metrical and nonmetrical contexts

Experiment 1 determined the fastest tempo at which participants could tap in synchrony with every nth tone (n = 2 to 9) in an isochronous sequence. Tapping was difficult with every 5th or 7th tone but easy with every 2nd, 4th, or 8th tone, suggesting that evenly divisible groups of n tones are automatically subdivided into equal groups of 2 or 3-a form of auditory subitizing that generates metrical hierarchies commonly found in Western music. Experiments 2 and 3 sought evidence of subitizing and subdivision in timed explicit enumeration of short, rapidly presented tone sequences (n = 2 to 10). Enumeration accuracy decreased monotonically with n. Response time increased monotonically up to n = 5 or 6, but less between 2 and 3 than between 3 and 4. Thus, a single group of 2 or 3 tones perhaps can be subitized, but subdivision of larger groups into subgroups of 2 or 3 tones seems to be specific to a repetitive, metrical context.     

An event-coder for evoked potential studies

A device is described which has 10 input and 2 output lines. Grounding an input causes a pulse with a specific amplitude, polarity, and duration to appear on one of the output lines. Pulse parameters can be set by front-panel controls. Thus, 10 distinct events can be coded by associating a unique pulse with each event. These pulses can be recorded on one (or two) channels of a magnetic tape recorder for subsequent processing. The use of this coder in the study of event-related potentials is described.     

Perception and production of tone in aphasia

An acoustical and perceptual study of lexical tone was conducted to evaluate the extent and nature of tonal disruption in aphasia. The language under investigation was Thai, a tone language which has five lexical tones--mid, low, falling, high, and rising. Subjects included six left brain-damaged aphasics (two Broca's, one transcortical motor, one global, one conduction, one Wernicke), one right brain-damaged nonaphasic, one cerebellar dysarthric, and five normals. High-quality tape recordings of each subject's productions of a minimal set of five, monosyllabic Thai words were presented to 10 adult Thai listeners for identification. Results from the phonemic identification tests indicated that tone production is relatively spared in aphasic patients with unilateral left hemisphere lesions. The performance of the global aphasic, however, was considerably below normal. Patterns of tonal confusions further revealed that the performance of all aphasics, except the global, differed from that of normal speakers primarily in degree rather than in kind. Tonal contrasts were signaled at a high level of proficiency by the right brain-damaged and dysarthric patients. Acoustical analysis revealed that F0 contours associated with the five tones for all aphasics, except the global, were similar in overall shape as well as position in the tone space to those of normals. F0 contours for the right brain-damaged patient and the dysarthric also generally agreed with those of normals in terms of shape and position. F0 ranges of both aphasic and nonaphasic brain-damaged speakers were generally larger than those of normals for all five tones. The relationship between tone and vowel duration was generally similar to that of normals for all brain-damaged speakers. A comparison of aphasics' performance on tone perception (J. Gandour & R. Dardarananda, 1983, Brain and Language, 18, 94-114) and tone production indicated that, for the normal and right brain-damaged subjects, performance on the perception task was higher than on production, whereas the opposite was true for the aphasics. These data are brought to bear on issues related to tone production in aphasia, consonant and vowel production in aphasia, hemispheric specialization for tone production, intonation production in aphasia, relationship between speech perception and speech production, and tone production in dysarthria with cerebellar disease.     

Clinical validation of a sleep assessment device

We have previously reported on the use of a sleep assessment device (SAD) with non-insomniac subjects. The SAD works by generating a brief, soft tone about every 10 min throughout the night and tape recording verbal responses to these cues. The sleep patterns reconstructed from the night's tape recordings proved highly concordant with EEG records. The present study tested the SAD against the EEG standard in 20 nights of monitoring chronic insomniacs. No significant differences were found between the SAD and EEG records with respect to sleep latency, duration of awakenings during the night, total sleep time and sleep efficiency percentage. The EEG detected many more very brief awakenings during the night than did the SAD due to the continuous monitoring by the former. The SAD proved to be a non-intrusive measure of sleep according to three independent measures. The usefulness of the SAD as a measure of sleep in the natural environment was discussed.     

The effect of dextroamphetamine on habituation of peripheral vascular response in children

The blood volume pulse (BVP) measured by a photoplethysmograph was recorded in 43 children with behavior and learning problems before and after either stimulant drug treatment or placebo. A series of twenty-four 750-cps tones was presented at 10-sec. intervals, with one trial having a doubled interval and one with a halved interval. A 1,000-cps tone was introduced following the 24th trial. As predicted, the drug-treated subjects showed significantly more rapid habituation to the tones. They also showed more variability of BVP following the longer intertriai interval, but showed less variability following the introduction of the high tone. The results are interpreted as showing that the stimulant has the effect of raising autonomie arousal level with consequently more rapid habituation of the orienting response.An earlier version of this article was presented to The Society for Psychophysiological Research, Monterey, California, October 1969. This research was supported by Grant No. MH14432 from the Psychopharmacology Section (National Institute of Mental Health) and Research Scientist Development Award No. K2MH7839 (National Institute of Mental Health).     

Top-down gain control in the auditory system: evidence from identification and discrimination experiments

The influence of intensity range in auditory identification and intensity discrimination experiments is well documented and is usually attributed to nonsensory factors. Recent studies, however, have suggested that the stimulus range effect might be sensory in origin. To test this notion, in one set of experiments, we had listeners identify the individual tones in a set. One baseline condition consisted of identifying four 1-kHz, low-intensity tones; the other consisted of identifying four 1-kHz, high-intensity tones. In the experimental conditions, these baseline tone sets were augmented by adding a fifth tone at either 1 or 5 kHz. Added 5-kHz tones had little effect on identification accuracy for the four baseline tones. When an added 1-kHz tone differed substantially in intensity from the four baseline tones, it adversely affected performance, with the addition of a high-intensity tone to a set of low-intensity tones having a more deleterious effect than the addition of a low-intensity tone to a set of high-intensity tones. These and further results, obtained in an exploration of this asymmetrical range effect in a third identification experiment and in two intensity-discrimination experiments, were consistent with the notion of a nonlinear amplifier under top-down control whose functions include protection against sensory overload from loud sounds. The identification data were well described by a signal-detection model using equal-variance Laplace distributions instead of the usual Gaussian distributions.     

Auditory adaptation to gradual rise or fall in intensity of a tone

The auditory system adapts to gradual changes of intensity. After listening to a gradually loudening (or softening) tone, a steady test tone appeared to be growing gradually softer (or louder). “Tuning curves” for these aftereffects were measured by adapting to one audio frequency and testing at another. Softening tones produced larger aftereffects, which were more sharply tuned for audiofrequency, than did loudening tones.     

Effects of feedback and calibration on the verbal estimation of the duration of tones

Two experiments investigated the effects of feedback (Experiment 1) and calibration (Experiment 2) on verbal estimation of the duration of tones ranging from 77 to 1183 ms in length. In Experiment 1, accurate feedback was provided after half the trials in the feedback condition, and this was contrasted with a no-feedback condition in which feedback was absent. In Experiment 2, in the calibration condition, participants estimated the duration of the second of two tones, after a first tone of a known duration (ranging from 50 to 1200 ms) had been presented. In the no calibration condition the value of the first tone was unknown. Compared with conditions without feedback or calibration, the feedback/calibration operation produced no significant change in group mean estimates, nor coefficients of variation of estimates, but the absolute deviation of estimates from the real stimulus duration, and the absolute deviation of individual estimates from the group mean, were both significantly reduced. The feedback/calibration thus made participants' mean estimates thus more accurate and more similar to one another, but the actual mechanism by which this was done was apparently a subtle process of adjustment, rather than a gross change in mean estimate or estimate variability.     

Perceptual grouping in audition

The present experiments evaluated the effect of relative frequency as a determinant of the figure-ground organization of sequences of auditory tones. Observers counted sequences of 20 ms tones that were presented at the same frequency or that alternated between two different frequencies. The alternating tones differed in frequency by one whole tone, seven tones, or nineteen tones. Counting accuracy increased with increases in the silent interval between the tones. When the alternating tones differed by seven or nineteen tones, counting was disrupted at rates of presentation of eight tones per second or slower. In contrast to this decrement in the counting of tones that alternated by over an octave, very little decrement was observed when the tones alternated by just one whole tone. The best subjects counted these alternating tones more accurately than the tones presented at the same frequency. The poorest subjects showed a small decrement even when the tones alternated by just one whole tone. The results were discussed in terms of determinants of figure-ground organization in auditory information processing.     

A programmable tone generator for presenting melodic and harmonic patterns in music research

This report describes the design of a programmable tone generator, a digitally controlled system for generating complex tones. The PTG will provide sequential series of single tones or simultaneously sounding two- and three-tone groups over a four-octave range. Programming of the PTG is accomplished by paper tape using a digital, binary configuration. The current version will interface with Grason-Stadler Series 1200 equipment.     

Effect on numerosity judgment of grouping of tones by auditory channels

Previous research suggests that numerosity judgments for sequences of tones improve when the sequence is structured such that equal and small groups of tones alternate between the ears. The present. study systematically investigates the effects of the structure of tone sequences on number judgment. Tone frequency is chosen as the grouping principle instead of spatial location. In the first experiment, sequences with equal groups of 2, 3, 4, 5, 6, or 7 tones (groups alternating between 800 and 1, 250 Hz) were compared with monotonous sequences. At a slow repetition rate of the tones (280 msec onset to onset), grouping the sequence deteriorated the numerosity judgment. At II fast repetition rate of the tones (100 msec onset to onset) grouping improved numerosity judgment, but only if the group size did not exceed 4 to 5 tones. In the second experiment, the equality of group size in the sequence as a necessary condition for the improvement was investigated. It was found that tone sequences comprised of equal groups were judged more accurately in number than sequences comprised of unequal groups. These results seem to give support for the existence of an auditory subitizing process. The results of this study are also compared with the results of studies in which sequences of tones, alternating one by om! between locations or frequencies, had to be judged in number.     

Pattern-directed attention in uncertain-frequency detection

The role of early pattern components as cues in uncertain frequency detection was investigated in four probe-signal experiments. Listeners heard two consecutive presentations of one of two 12-tone patterns in a noise background. One presentation of the pattern was complete, whereas the other was missing the 11th (primary) tone. Listeners were required to indicate which presentation was complete. On 20% of the test trials, the 11th component of the complete pattern was replaced with one of four probe tones. The results indicated that listeners were more sensitive to the primary tone than to probe tones, and this selective sensitivity changed on a trial-by-trial basis as a function of the attentional cues provided by early pattern components. The data suggested two cue functions: (1) an “informational” function in providing information regarding which of two primary tones is likely to occur on a given trial, and (2) a “frequency” function that “automatically” directs listening to an appropriate frequency range and narrows or “fine tunes,” the listening band.     

Recognition memory for pitch of fixed and roving stimulus tones

The method of delayed comparison was used to measure pitch memory under two conditions of presentation, either the same standard tone on every trial (fixed S) or one of four equally likely standard tones (roving S), six durations of interference interval ranging from 0.0 to 4.0 sec, and two types of interference interval, either blank or filled with a pure tone. Listeners were instructed not to rehearse the S tone during the interference interval. For both fixed-S and roving-S conditions, accuracy of performance, as measured by area under the ROC curve, declined as interval duration increased and declined more rapidly following an interference-filled than following a blank interval. In general, forgetting proceeded at a slower rate under fixed-S conditions than under roving-S conditions. A second experiment showed that very little forgetting is obtained over 4 sec for roving-S conditions if instructions permit rehearsal of the S tone and suggests that the conclusions from the first experiment be restricted to nonrehearsal instructional conditions.     

Vowel quality changes produced by surrounding tone sequences

In three experiments, we examined whether energy at the same frequency as one of a vowel's harmonics in the F1 region can be captured by a preceding or following sequence of tones. The position of the /I/-/E/ phoneme boundary along an F1 continuum was used to assess the extent of capture. The first two experiments showed that a sequence of tones at 500 Hz (56-msec duration at 10/sec) can perceptually remove added energy at 500 Hz from a steady vowel (F0 = 125 Hz) that forms part of the sequence. The effect is detectable with one preceding tone, asymptotes with four, and is greater when two tones follow the vowel than when none do. Rising and falling sequences of tones (at 62.5-Hz intervals or at whole-tone intervals) differ in their effect. Falling sequences behave much like constant tones at 500 Hz but with less effect, whereas rising sequences show no evidence of removing the added tone. The second experiment replicated the first and also showed that when the vowel is embedded in a rising or a falling sequence of tones that continue after it, the following tones have no effect. The third experiment suggested that the different effects found with rising versus falling sequences are qualitatively predictable on the basis of the additive effects of their constituent tones rather than by virtue of their contour. The experiments indicated that sequences of repeating tones are much more effective at capturing a harmonic from a vowel than are sequences that follow a simple pattern. This result may reflect the operation of a principle of least commitment in auditory grouping.     

A computerized system for recording and analysis of self-observations of couples’ interaction

This paper describes a method for recording couples’ observations of their communications during an ongoing interaction sequence. The procedure allows the recording and decoding of immediate reactions, while maintaining an ecologically valid observation environment. Responses are encoded on a stereo cassette tape player and are decoded by a PDP-11/10 computer with two Schmitt triggers that count the peaks in the tones. The computer provides analysis of the response value and time. Applications for other research problems in the areas of social and applied clinical psychology are discussed.     

The additivity of loudness across critical bands: A conjoint measurement approach

Five subjects were required in each trial to compare directly two sounds and to indicate which sound was louder. Each of the 64 sounds employed consisted of a combination of one of eight intensity levels of a 2-kHz tone and one of eight intensities of a 5-kHz tone. If, as Fletcher and Munson (1933) argued, loudness is additive for tone combinations in which the frequencies are widely separated, then subjects’ judgments should reflect the summed loudnesses of the 2- and 5-kHz tones in a two-tone combination. Judgments of individual subjects were shown to satisfy the conditions for an additive structure, and individual loudness scales were constructed. These loudness scales varied from subject to subject. Since this paired comparison procedure minimized response biases, the results suggest substantial individual differences in the sensory representation of sound intensity. The relations among sensory scales derived from other structured sensory judgments, such as binaural loudness, are discussed.     

Interference effects in tone memory

Memory for a standard tone in comparison to a subsequent test tone was examined in three experiments with three intervening tones between the standard and test tones. In each trial, the intervening tones were presented from one of seven frequency range and distance from the standard tone conditions. Experiment 1 tone patterns were played at four different presentation rates, and the subjects judged whether the test was higher or lower than the standard. Memory interference effects caused by the different intervening tone conditions could be accounted for by a directional shift in the standard tone memory toward the intervening tones and by a general decrease in the standard tone memory strength with more distant intervening tones. Interference effects were smaller for the rapid presentation rates because the intervening tones formed separate "perceptual streams." Two additional experiments presented the tone patterns in a task requiring the subjects to match a continuously variable tone to their memory of the standard (Experiment 2) and a task requiring them to judge whether the standard and test tones were the "same" or "different" (Experiment 3). These experiments showed large differences in interference effects as a function of the required judgment and the subjects' musical experience.     

Tonal hierarchies in the music of north India

Cross-culturally, most music is tonal in the sense that one particular tone, called the tonic, provides a focus around which the other tones are organized. The specific organizational structures around the tonic show considerable diversity. Previous studies of the perceptual response to Western tonal music have shown that listeners familiar with this musical tradition have internalized a great deal about its underlying organization. Krumhansl and Shepard (1979) developed a probe tone method for quantifying the perceived hierarchy of stability of tones. When applied to Western tonal contexts, the measured hierarchies were found to be consistent with music-theoretic accounts. In the present study, the probe tone method was used to quantify the perceived hierarchy of tones of North Indian music. Indian music is tonal and has many features in common with Western music. One of the most significant differences is that the primary means of expressing tonality in Indian music is through melody, whereas in Western music it is through harmony (the use of chords). Indian music is based on a standard set of melodic forms (called rags), which are themselves built on a large set of scales (thats). The tones within a rag are thought to be organized in a hierarchy of importance. Probe tone ratings were given by Indian and Western listeners in the context of 10 North Indian rags. These ratings confirmed the predicted hierarchical ordering. Both groups of listeners gave the highest ratings to the tonic and the fifth degree of the scale. These tones are considered by Indian music theorists to be structurally significant, as they are immovable tones around which the scale system is constructed, and they are sounded continuously in the drone. Relatively high ratings were also given to the vadi tone, which is designated for each rag and is given emphasis in the melody. The ratings of both groups of listeners generally reflected the pattern of tone durations in the musical contexts. This result suggests that the distribution of tones in music is a psychologically effective means of conveying the tonal hierarchy to listeners whether they are familiar with the musical tradition. Beyond this, only the Indian listeners were sensitive to the scales (thats) underlying the rags. For Indian listeners, multidimensional scaling of the correlations between the rating profiles recovered the theoretical representation of scales described by theorists of Indian music.(ABSTRACT TRUNCATED AT 400 WORDS)     

Fear imagery and the startle-probe reflex

Blink reflexes to acoustic probes, heart rate, and subjective reports were studied during affective memory imagery. Thirty-six undergraduates memorized 6 pairs of neutral and fearful sentences. After learning each pair, they relaxed and listened to a series of uniform tones, one every 6 s. A change in tone pitch (higher or lower) cued recall of one of the two sentences. At the first cue tone, groups (n = 12) were under different instructions: (a) ignore the sentence and relax, (b) silently articulate the sentence, and (c) imagine the sentence content as a personal experience. At the second cue tone, all subjects performed the imagery task. Startle probes (50-ms, 95-dB white noise) were presented unpredictably during relaxation and recall trials. Probe blink reflexes were larger and cardiac rate faster at fear sentence recall than at neutral sentence recall or relaxation. For probe reflexes, this effect was greater for imagery than for nonsemantic recall tasks.