Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pitch Discrimination”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources
PubMed1987

Perceptual organization of acoustic stimuli by budgerigars (Melopsittacus undulatus): I. Pure tones.

A new combination of operant conditioning and psychophysical scaling procedures was used to study auditory perception in a small bird. In a same-different discrimination task, budgerigars learned to discriminate among pure tones that varied along one or more acoustic dimensions. Response latencies were used to generate a matrix of interstimulus similarities. Multidimensional scaling procedures were used to arrange these acoustic stimuli in a multidimensional space that supposedly reflects the bird's perceptual organization. For tones that varied in intensity, duration, and frequency simultaneously, budgerigars were much more sensitive to frequency changes. From a set of tones that varied only in intensity, it was possible to calculate the growth of loudness with intensity for the budgerigar. For tones that varied only in frequency, budgerigars showed evidence of an "acoustic fovea" for frequency change in the spectral region of 2-4 kHz. Budgerigars and humans also differed in their perceptual grouping of tone sequences that rise, fall, or remain constant in pitch. Surprisingly, budgerigars were much less responsive to pitch contour than were humans.

Animals↗
PubMed2006

Auditory processing deficits in dyslexia: task or stimulus related?

The nature of the fundamental deficit underlying reading disability is the subject of a long-standing debate. We previously found that dyslexics with additional learning difficulties (D-LDs) perform poorly in simple auditory tasks. We now tried to determine whether these deficits relate to stimulus or task complexity. We found that the degree of impairment was dependent on task rather than stimulus complexity. D-LDs could adequately detect and identify mild frequency changes in simple pure tones and minimal phonemic changes in complex speech sounds when task required only simple same-different discriminations. However, when task required the identification of the direction of frequency change or the ordinal position of a repeated tonal or speech stimulus, D-LDs' performance substantially deteriorated. This behavioral pattern suggests that D-LDs suffer from a similar type of deficits when processing speech and nonspeech sounds. In both cases, the extent of difficulties is determined by the structure of the task rather than by stimulus composition or complexity.

Acoustic Stimulation↗
PubMed1989

Frequency difference limens in normal and sensorineural hearing impaired chinchillas.

This study assessed normal frequency discrimination ability in the chinchilla and determined how this ability changes as a function of an experimentally induced sensorineural hearing loss. Four chinchillas were trained by the methods of positive reinforcement to report absolute thresholds and frequency difference limens (FDLs). Subjects were then treated with the aminoglycosidic antibiotic amikacin until a 30-dB hearing loss was measured at 10.0 kHz. Absolute and frequency difference thresholds were determined during and after drug treatment. When post-drug thresholds had stabilized, subjects were sacrificed and their cochleas stained, embedded in plastic, microdissected, and viewed with phase contrast microscopy to permit examination of the cochlear tissue. Post-drug data suggest that frequency discrimination at a high frequency is unaffected by a 40- to 45-dB sensorineural hearing loss, considerable hair cell damage, and the resultant disruption of the cochlear micromechanics. The data, in concert with previously published reports, suggest that FDLs may be less affected by a high-frequency sensorineural hearing loss than by a low-frequency sensorineural hearing loss.

Amikacin↗
PubMed2003

Vertical-plane sound localization probed with ripple-spectrum noise.

Ripple-spectrum stimuli were used to investigate the scale of spectral detail used by listeners in interpreting spectral cues for vertical-plane localization. In three experiments, free-field localization judgments were obtained for 250-ms, 0.6-16-kHz noise bursts with log-ripple spectra that varied in ripple density, peak-to-trough depth, and phase. When ripple density was varied and depth was held constant at 40 dB, listeners' localization error rates increased most (relative to rates for flat-spectrum targets) for densities of 0.5-2 ripples/oct. When depth was varied and density was held constant at 1 ripple/oct, localization accuracy was degraded only for ripple depths > or = 20 dB. When phase was varied and density was held constant at 1 ripple/oct and depth at 40 dB, three of five listeners made errors at consistent locations unrelated to the ripple phase, whereas two listeners made errors at locations systematically modulated by ripple phase. Although the reported upper limit for ripple discrimination is 10 ripples/oct [Supin et al., J. Acoust. Soc. Am. 106, 2800-2804 (1999)], present results indicate that details finer than 2 ripples/oct or coarser than 0.5 ripples/oct do not strongly influence processing of spectral cues for sound localization. The low spectral-frequency limit suggests that broad-scale spectral variation is discounted, even though components at this scale are among those contributing the most to the shapes of directional transfer functions.

Acoustic Stimulation↗
PubMed2006

A comparison of adaptive procedures for rapid and reliable threshold assessment and training in naive listeners.

In psychoacoustic studies there is often a need to assess performance indices quickly and reliably. The aim of this study was to establish a quick and reliable procedure for evaluating thresholds in backward masking and frequency discrimination tasks. Based on simulations, four procedures likely to produce the best results were selected, and data collected from 20 naive adult listeners on each. Each procedure used one of two adaptive methods (staircase or maximum-likelihood estimation, each targeting the 79% correct point on the psychometric function) and two response paradigms (3-interval, 2-alternative forced-choice AXB or 3-interval; 3-alternative forced-choice oddball). All procedures yielded statistically equivalent threshold estimates in both backward masking and frequency discrimination, with a trend to lower thresholds for oddball procedures in frequency discrimination. Oddball procedures were both more efficient and more reliable (test-retest) in backward masking, but all four procedures were equally efficient and reliable in frequency discrimination. Fitted psychometric functions yielded similar thresholds to averaging over reversals in staircase procedures. Learning was observed across threshold-assessment blocks and experimental sessions. In four additional groups, each of ten listeners, trained on the different procedures, no differences in performance improvement or rate of learning were observed, suggesting that learning is independent of procedure.

Adult↗
PubMed1981

Factors in the discrimination of tonal patterns. III. Frequency discrimination with components of well-learned patterns.

Estimates of the effectiveness of selective auditory attention were obtained by adjusting the level of a target tone, which was presented as one 40-msec component in a ten-tone sequential pattern. When the levels of target and nontarget tones were the same, frequency-discrimination thresholds (delta f/f) following prolonged training varied from 0.01-0.02 for minimal-uncertainty testing conditions to 0.1-0.2 under high trial-to-trial stimulus uncertainty. The functions relating frequency discrimination to target-tone level are widely separated for the two conditions; comparing them, we conclude that the effects of selective auditory attention can be equated to a 50-dB variation in signal level. Patterns that had been well-learned during the minimal-stimulus (remembered standard) procedure. The results of these latter experiments are consistent with a "top-down" processing interpretation in which well-learned patterns are first identified to locate the portions requiring further resolution.

Acoustics↗
PubMed1985

Frequency discrimination in bobwhite quail (Colinus virginianus).

Bobwhite quail (Colinus virginianus) (N:9, aged 24 mo) were trained using a positive reinforcement paradigm to respond to an assigned "standard" frequency of either 1.0 or 3.5 kc/s by pressing a response key. Each S was trained in 2 phases to respond to its assigned frequency rather than to alternately presented tones of a different frequency. In every test each S discriminated its assigned frequency at greater than chance levels. Discrimination ability was poorest when delta F was at the minimum tested (0.25 kc/s). Birds whose standard frequency was 1.0 kc/s were better at the task than those trained to a 3.5-kc/s standard, especially when finer discriminations were required (Phase II). This superiority at 1.0 kc/s confirmed what was seen previously (Barton et al, J. Aud. Res., 1984, 24, 87-97) in the Bobwhite's audibility curve; it was hypothesized that the correspondence may have to do with the need for adult birds to recognize frequency variations near 1.0 kc/s that are uniquely made by immediate conspecifics rather than other members of the species. As such it may well represent a "fine tuning" of the bird's acoustic abilities.

Animals↗
PubMed2003

The developmental origins of musicality.

The study of musical abilities and activities in infancy has the potential to shed light on musical biases or dispositions that are rooted in nature rather than nurture. The available evidence indicates that infants are sensitive to a number of sound features that are fundamental to music across cultures. Their discrimination of pitch and timing differences and their perception of equivalence classes are similar, in many respects, to those of listeners who have had many years of exposure to music. Whether these perceptual skills are unique to human listeners is not known. What is unique is the intense human interest in music, which is evident from the early days of life. Also unique is the importance of music in social contexts. Current ideas about musical timing and interpersonal synchrony are considered here, along with proposals for future research.

Animals↗
PubMed1992

Modulation discrimination interference and auditory grouping.

The detection of a change in the modulation pattern of a (target) carrier frequency, fc (for example a change in the depth of amplitude or frequency modulation, AM or FM) can be adversely affected by the presence of other modulated sounds (maskers) at frequencies remote from fc, an effect called modulation discrimination interference (MDI). MDI cannot be explained in terms of interaction of the sounds in the peripheral auditory system. It may result partly from a tendency for sounds which are modulated in a similar way to be perceptually 'grouped', i.e. heard as a single sound. To test this idea, MDI for the detection of a change in AM depth was measured as a function of stimulus variables known to affect perceptual grouping, namely overall duration and onset and offset asynchrony between the masking and target sounds. In parallel experiments, subjects were presented with a series of pairs of sounds, the target alone and the target with maskers, and were asked to rate how clearly the modulation of the target could be heard in the complex mixture. The results suggest that two factors contribute to MDI. One factor is difficulty in hearing a pitch corresponding to the target frequency. This factor appears to be strongly affected by perceptual grouping. Its effects can be reduced or abolished by asynchronous gating of the target and masker. The second factor is a specific difficulty in hearing the modulation of the target, or in distinguishing that modulation from the modulation of other sounds that are present. This factor has effects even under conditions promoting perceptual segregation of the target and masker.

Acoustic Stimulation↗
PubMed1985

Dissociation of endogenous components of auditory evoked potentials following carbachol microinjection into the cholinoceptive pontine inhibitory area.

Microinjections of the cholinergic agonist, carbachol, into an area ventromedial to the principal nucleus of the locus coeruleus produce pronounced suppression of postural somatomotor and sympathetic visceromotor functions, and profound unresponsiveness to external stimuli. In order to clarify whether this unresponsiveness is due exclusively to disruption of motor components of various behavioral responses, we examined changes in the endogenous components of auditory evoked potentials recorded in conjunction with a tone discrimination task. Concomitant with carbachol-induced behavioral unresponsiveness, the late positive component (LPC) at 250-350 ms disappeared, while the early positive component at 80-150 ms was enhanced. This result suggests that, after the onset of carbachol-induced behavioral unresponsiveness, external stimuli enter the brain but are not integrated in neural processes reflected in LPC which has previously been implicated in processes mediating orienting responses, selective attention, and/or cognitive evaluation.

Animals↗
PubMed1990

Studies in auditory timing: 2. Rhythm patterns.

Listeners discriminated between 6-tone rhythmic patterns that differed only in the delay of the temporal position of one of the tones. On each trial, feedback was given and the subject's performance determined the amount of delay on the next trial. The 6 tones of the patterns marked off 5 intervals. In the first experiment, patterns comprised 3 "short" and 2 "long" intervals: 12121, 21121, and so forth, where the long (2) was twice the length of a short (1). In the second experiment, patterns were the complements of the patterns in the first experiment and comprised 2 shorts and 3 longs: 21212, 12212, and so forth. Each pattern was tested 45 times (5 positions of the delayed tone x 3 tempos x 3 replications). Consistent with previous work on simple interval discrimination, absolute discrimination (delta t in milliseconds) was poorer the longer the intervals (i.e., the slower the tempo). Measures of relative discrimination (delta t/t, where t was the short interval, the long interval, or the average of 2 intervals surrounding the delayed tone) were better the slower the tempo. Beyond these global results, large interactions of pattern with position of the delayed tone and tempo suggest that different models of performance are needed to explain behavior at the different tempos. A Weber's law model fit the slow-tempo data better than did a model based on positions of "natural accent" (Povel & Essens, 1985).

Adult↗
PubMed2005

How well can anaesthetists discriminate pulse oximeter tones?

The ability of experienced anaesthetists to discern oxygen saturation by listening to the tones of a Datex AS3 pulse oximeter was examined. Five-second samples were recorded using a high fidelity patient simulator and replayed singly and in pairs. Whilst the lower saturations were generally recognized as lower, the perceived range was greatly compressed. Median perceived estimates for 70% saturation was 89%, for 80% was 93% and for 94% was 94%. When comparing pairs of samples, the direction of the difference was correctly discerned by 70% of anaesthetists for differences of 2%, rising to 95% for differences of greater than 8% oxygen saturation. The magnitude of the difference was consistently underestimated. With an actual difference of 20%, the median estimate was 5%. The results indicate that while qualitative estimate changes in oxygen saturation are moderately reliable, quantitative estimation is severely limited by a compromised perceived scale. This may lead to underestimation of the severity if the auditory signal is relied on in isolation. A non-linear (musical) scale may prove more appropriate and should be investigated. Testing experienced anaesthetists demonstrated that most could detect the direction, but not the magnitude of a change in saturation by listening to the change in pitch of a Datex AS3 pulse oximeter tone.

Adult↗
PubMed1997

Tone duration discrimination in Parkinson's disease.

Patients with Parkinson's disease (PD) and healthy controls took a computerized test of tone duration discrimination (TDD) using pairs of tones of 0.4-1.6 sec duration, presented at intervals of 0.5-4 sec. In PD patients as well as controls, TDD was impaired by even slight degrees of cognitive deterioration. PD yielded impaired TDD in females, but not in males. This suggests that the dopamine-powered biological clock, which is vulnerable to PD, is more important for the processing of durations in the 1-sec range in women than in men.

Adult↗
PubMed2001

Sources of variation in profile analysis. I. Individual differences and extended training.

This study investigated two sources of variance in the ability to discriminate auditory profiles: individual differences and extended training. The goals of the study were (1) to determine the range and origins of individual differences in profile analysis and (2) to determine whether those who initially had poor sensitivity to changes in spectral shape could eventually acquire finer sensitivity. Profile stimuli had 11 components with equal-log spacing from 200-2200 Hz. Thresholds ranged from - 1 to -25 dB (signal level relative to the context level) across 46 listeners. The correlation between spectral-shape discrimination thresholds after 2000 trials and pure-tone intensity-discrimination thresholds was 0.36. The range of individual differences for pure-tone intensity discrimination and spectral-shape discrimination was about the same. Two groups of listeners were given extended practice on the profile task, one group that showed low thresholds after an initial 2000 trials of practice and another that showed much higher initial thresholds. All listeners improved during the course of the first 2000 trials of training. Most of the poor listeners continued to improve during 9000 trials of training. Individual differences in the listeners' sensitivity to changes in spectral shape still existed after the extended practice.

Adult↗
PubMed2004

A molecular description of profile analysis: decision weights and internal noise.

Systematic inefficiencies and internal noise in a spectral profile discrimination task were investigated. Listeners detected a 1000-Hz sinusoid added in-phase to the central component of a complex consisting of 11 equal-intensity sinusoids. Parameters for a channel model that employs decision weights and internal noise were estimated with molecular psychophysical techniques. Maximum likelihood predictions of the model were generally within a few decibels of observed thresholds. The degree to which an assumption of ideal weights leads to overestimation of internal noise was also assessed.

Adult↗
PubMed1996

Perceptual integrality of major chord components.

In the present study, an accuracy, rather than a reaction time, version of the Garner paradigm was used to evaluate the integrality or separability of major chord components. Tuned (prototype, or P) and mistuned (nonprototype, or NP) sets of root position C-major triads were constructed by holding the C constant in all stimuli and varying the E and G frequencies in 2- and 4-Hz steps. The P stimuli represent small systematic mistunings in the E and G notes relative to an equal-tempered C-major chord. The NP stimuli represent an equivalent range of frequency variation, but relative to a significantly out-of-tune C-major triad. In different experimental sessions, a same-different (AX) task was used to separately evaluate discrimination performance for the E and G frequencies as a function of whether the nontarget frequency (G or E) was fixed or varied in either a correlated or an orthogonal fashion (with the C frequency always held constant). Compared with a fixed baseline condition where only the target frequency changed, both chord components exhibited a significant redundancy gain in the correlated conditions and, to varying degrees, significant interference effects in the orthogonal condition, indicating that the chord components function largely in an integral fashion. Relative to the discrimination of G, discrimination of the E frequency was less influenced by variation in the nontarget (G) frequency, showing that attention, to some degree, could be selectively allocated to the E chord component. In addition, the results were consistent with previous findings that the functional prototype for the major chord category seems to act as a perceptual anchor, rather than as a magnet, and appears to be located in the physiologically defined area of just temperament, as opposed to the more experientially defined area of equal temperament.

Adult↗
PubMed1988

Selective attention in the presence of music: an event-related potentials (ERP) study.

The present study was aimed at investigating selective attention in the presence of music as expressed by ERPs. The experiments were performed with 7 subjects. A two-channel auditory frequency discrimination task (target - 1000 Hz, standard - 1550 Hz tones) in a dichotic listening environment was employed. The EEG was recorded from Fz, Cz, Pz, C3 and C4. The EOG and performance data were also collected. A smaller and delayed N1 amplitude as well as changes in the two components of the processing negativity in the presence of music were found. N2 and P3 components only delay with music was observed. The changes in the level of performance were not significant.

Adult↗
PubMed2003

Dynamics of working memory for moving sounds: an event-related potential and scalp current density study.

Human brain imaging studies have suggested that posterior temporo-parietal regions are involved in auditory spatial processing. We used electroencephalography to investigate the dynamics of temporo-parietal networks during working memory for moving sounds. A delayed matching-to-sample task required a decision on the identity of positions and trajectories of two moving sounds S1 and S2 presented with delays of 927 or 1427 ms. Moving sounds consisted of noise bursts positioned at successive angles to create the impression of one of six possible trajectories at variable spatial positions. Stimuli in the equally difficult control condition were identical to the memory task up to S2, which was replaced by a spatial displacement in the otherwise stationary background sound whose direction had to be detected. Event-related potentials were recorded from 31 scalp electrodes in 15 subjects. Scalp current density estimates allowed to identify the following components. The fronto-central negative variation preceding S2 did not differ between tasks. In contrast, the sustained negative current during the presentation of S1 originating from superior temporal cortex was more pronounced for the memory task, probably reflecting enhanced attention allocation and foreground-background discrimination. Most importantly, the memory task activated current sources over bilateral posterior parietal regions between the middle of S1 and the end of the delay phase. This component was completely absent in the control condition. In summary, the present study disclosed varying degrees of memorization-related, top-down driven influences on the processing of moving sounds at different stages of an auditory network involving temporal and parietal regions.

Acoustic Stimulation↗