Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pitch Perception”

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 847 records · Page 47Linked to original sources

Temporal discrimination as a function of marker duration.

In a series of three experiments, the effect of marker duration on temporal discrimination was evaluated with empty auditory intervals bounded by markers ranging from 3 to 300 msec or presented as a gap within a continuous tone. As a measure of performance, difference thresholds in relation to a base duration of 50 msec were computed. Performance on temporal discrimination was significantly better with markers ranging from 3 to 150 msec than with markers ranging from 225 to 300 msec or under the gap condition. However, within each range of marker duration (3-150 msec; 225-300 msec or gap) performance did not differ significantly. A fourth experiment provided evidence that the effect of marker duration cannot be explained in terms of marker-induced masking. A good approximation of the relationship between marker duration and temporal discrimination performance in the present experiments is a smooth step function, which can account for 99.3% of the variance of mean discrimination performance. Thus, the findings of the present study point to the conclusion that two different mechanisms are used in the processing of temporal information, depending on the duration of the auditory markers. The tradeoff point for the hypothetical shift from one timing mechanism to the other may be found at a marker duration of approximately 200 msec.

Adult↗

Perception of aperiodicities in synthetically generated voices.

The purpose of this study was to investigate univariate relationships between perceived dysphonia and variation in pitch perturbation, amplitude perturbation, and additive noise. A time-domain, pitch-synchronous synthesis technique was used to generate sustained vowels varying in each of the three acoustic dimensions. A panel of trained listeners provided direct magnitude estimates of roughness in the case of the stimuli varying in pitch and amplitude perturbation, and breathiness in the case of the stimuli varying in additive noise. Very strong relationships were found between perceived roughness and either pitch or amplitude perturbation. However, unlike results reported previously for nonspeech stimuli, the subjective quality associated with pitch perturbation was quite different from that associated with amplitude perturbation. Results also showed that perceived roughness was affected not only by the amount of perturbation, but also by the degree of correlation between adjacent pitch or amplitude values. A strong relationship was found between perceived breathiness and signal-to-noise ratio. Contrary to previous findings, there was no interaction between signal-to-noise ratio and the amount of high-frequency energy in the periodic component of the stimulus: Stimuli with similar signal-to-noise ratios received similar ratings, regardless of differences in the spectral slope of the periodic component.

Acoustic Stimulation↗

Thresholds for segregating a narrow-band from a broadband noise based on interaural phase and level differences.

Either an interaural phase shift or level difference was introduced to a narrow section of broadband noise in order to measure the acuity of the binaural system to segregate a narrowband from a broadband stimulus. Listeners were asked to indicate whether this dichotic noise or a totally diotic noise was presented in a single-interval procedure. Thresholds for interaural phase and level differences were estimated from four point psychometric functions. These thresholds were determined for three bandwidths of interaurally altered noise (2, 10, and 100 Hz) centered at four center frequencies (200, 500, 1000, and 1600 Hz). Thresholds were lowest when the interaurally altered band of noise was centered at 500 Hz, and thresholds increased as the bandwidth of the interaurally altered noise decreased. Performance did not exceed 75% correct when either an interaural phase shift (180 degrees) or interaural level difference (50 dB) was introduced to a 100 Hz band of noise centered at frequencies higher than 1600 Hz. In a second set of conditions, performance was measured when both an interaural phase shift and level difference were presented in a 10-Hz-wide band of noise centered at 500 Hz. A version of the Durlach E-C model was able to account for a great deal of the data. The results are discussed in terms of the Huggins dichotic pitch.

Attention↗

Similarities of vowels in nonreverberant and reverberant fields.

Perceptual distances among single tokens of American English vowels were established for nonreverberant and reverberant conditions. Fifteen vowels in the phonetic context (b-t), embedded in the sentence "Mark the (b-t) again" were recorded by a male talker. For the reverberant condition, the sentences were played through a room with a reverberation time of 1.2 s. The CVC syllables were removed from the sentences and presented in pairs to ten subjects with audiometrically normal hearing, who judged the similarity of the syllable pairs separately for the nonreverberant and reverberant conditions. The results were analyzed by multidimensional scaling procedures, which showed that the perceptual data were accounted for by a three-dimensional vowel space. Correlations were obtained between the coordinates of the vowels along each dimension and selected acoustic parameters. For both conditions, dimensions 1 and 2 were highly correlated with formant frequencies F2 and F1, respectively, and dimension 3 was correlated with the product of the duration of the vowels and the difference between F3 and F1 expressed on the Bark scale. These observations are discussed in terms of the influence of reverberation on speech perception.

Adolescent↗

Stimulus intensity and fundamental frequency effects on duplex perception.

Duplex perception occurs when part of the acoustic signal is used for both a speech and a nonspeech percept. This phenomenon has been interpreted as evidence of a distinct system for speech perception that precedes other specialized systems of general auditory processing (such as auditory grouping, and perception of pitch, loudness, and timbre). This interpretation was investigated by using an intensity-dependent form of duplex perception with the acoustic pair /da/ and /ga/. The "base" portion of the stimulus, common to both, consisted of the first and second formants and the steady-state portion of the third formant (F3). The F3 transition (either a sinusoid or a true formant), which cued the difference between /da/ and /ga/, was varied in intensity and fundamental frequency (F0). For every subject, the level at which each type of F3 transition was barely audible in the context of the base, i.e., duplex perception threshold, was first established. Next, identification functions were obtained by varying the intensity of the F3 transition relative to each subject's duplex perception threshold. Results revealed that duplex perception thresholds decreased as the F0 of the F3 transition increasingly differed from the base. Also, identification functions showed that, as has been previously demonstrated, the F3 transition contributed to the speech percept over a wide range of intensities and fundamental frequencies. However, as F3 transition intensity increased well above duplex perception threshold, /ga/ identification decreased. Also, both /da/ and /ga/ identification progressively decreased as the F0 of the F3 transition increasingly differed from the base. Contrary to previous duplex perception reports, such findings indicate that both intensity and F0 information is available to the specialized speech perception system. Thus, the computations of the speech perception system and its relation to the general auditory processing systems need to be reexamined.

Adult↗

The auditory n100m response reflects changes in speech fundamental frequency.

We studied the cortical activation underlying perception of variations in speech fundamental frequency (F0) as indexed by the amplitude, latency and source location of the auditory N100m response registered with magnetoencephalography (MEG). Ten subjects were presented with Finnish vowels with either a constant or an ascending/descending F0. We found that the human auditory cortex is sensitive to these time-varying changes in the F0 of speech: vowels with a constant F0 elicited more prominent N100m responses than did vowels with ascending or descending changes in F0. These results suggest that the speech-related behavior of the N100m arises out of cortical sensitivity to variations in the F0 and its harmonics which underlie the perception of pitch and intonation. The present observations are interpreted in terms of the interrelatedness of speech production and perception.

Acoustic Stimulation↗

The neurochrome. An identity preserving representation of activity patterns from neural populations.

Recording of simultaneous but separated activity of neural populations overwhelms the experimenter with a large amount of information. A clearly structured display technique the "Neurochrome" is introduced, usable on-line and real-time. It shows neural activity patterns while preserving neural identity by employing a color code. The Neurochrome assists the experimenter in generating and verifying hypotheses about neural correlations and stimulus-event relations already during the experiment. In auditory research single neurons are characterized by their spectro-temporal sensitivity to auditory stimuli. A straightforward generalization of this concept, applicable to neural populations, is proposed leading to a global indication of a populations' activity to stimuli: the Multi-Unit Spectro-Temporal Sensitivity. This approach is inversely related to the Neurochrome, the latter however containing more information. The combination of both approaches seems quite powerful in the investigation of neural assemblies. The procedures are illustrated with examples of extracellular multiunit recordings from the auditory midbrain of the grassfrog (Rana temporaria L.).

Animals↗

Perceptual interaction between carrier periodicity and amplitude-modulation in the gerbil (Meriones unguiculatus).

Due to its extended low-frequency hearing, the Mongolian gerbil (Meriones unguiculatus) has become a well-established animal model for human auditory processing. Here, two experiments are presented which quantify the gerbil's sensitivity to amplitude modulation (AM) and carrier periodicity (CP) in broad-band stimuli. Two additional experiments investigate a possible interaction of the two types of periodicity. The results show that overall sensitivity to AM and CP is considerably less than in humans (by at least 10 dB). The gerbil's amplitude-modulation sensitivity is almost independent of modulation frequency up to a modulation frequency of 1 kHz. Above, amplitude-modulation sensitivity deteriorates dramatically. On the basis of individual animals, carrier-periodicity detection may improve with increasing fundamental frequency up to about 500 Hz or may be independent of fundamental frequency. Amplitude-modulation thresholds are consistent with the hypothesis that intensity difference limens in the gerbil may be considerably worse than in humans, leading to the relative insensitivity for low modulation frequencies. Unlike in humans, inner-ear filtering appears not to limit amplitude-modulation sensitivity in the gerbil. Carrier-periodicity sensitivity changes with fundamental frequency similar to humans. Unlike in humans, there is no systematic interaction between AM and CP in the gerbil. This points to a relatively independent processing of the perceptual cues associated with AM and CP.

Acoustic Stimulation↗

Spatial attentional shifts: implications for the role of polysensory mechanisms.

Simple reaction times to lateralized visual (Experiment 1) or auditory (Experiment 2) targets were studied in normal subjects. The targets were preceded by a visual or auditory cue located on the same (valid cue), or opposite (invalid cue) side as the subsequent target, or on both sides (neutral cue), with one of four cue target intervals. The validity of visual and auditory cues influenced the speed of response to the visual target but not to the auditory target. It is hypothesized that cross-modal cueing of spatial position works only with modalities for which a movement (e.g. saccade) leads to improved sensory analysis.

Adult↗

The role of spatial complexity in the perception of speech and pure tones in dichotic listening.

Ear advantages for CV syllables were determined for 28 right-handed individuals in a target monitoring dichotic task. In addition, ear dominance for dichotically presented tones was determined when the frequency difference of the two tones was small compared to the center frequency and when the frequency difference of the tones was larger. On all three tasks, subjects provided subjective separability ratings as measures of the spatial complexity of the dichotic stimuli. The results indicated a robust right ear advantage (REA) for the CV syllables and a left ear dominance on the two tone tasks, with a significant shift toward right ear dominance when the frequency difference of the tones was large. Although separability ratings for the group data indicated an increase in the perceived spatial separation of the components of the tone complex across the two tone tasks, the separability judgment ratings and the ear dominance scores were not correlated for either tone task. A significant correlation, however, was evidenced between the laterality measure for speech and the judgment of separability, indicating that a REA of increased magnitude is associated with more clearly localized and spatially separate speech sounds. Finally, the dominance scores on the two tone tasks were uncorrelated with the laterality measures of the speech task, whereas the scores on the tone tasks were highly correlated. The results suggest that spatial complexity does play a role in the emergence of the REA for speech. However, the failure to find a relationship between speech and nonspeech tasks suggest that all perceptual asymmetries observed with dichotic stimuli cannot be accounted for by a single theoretical explanation.

Acoustic Stimulation↗

Locating the initial stages of speech-sound processing in human temporal cortex.

It is commonly assumed that, in the cochlea and the brainstem, the auditory system processes speech sounds without differentiating them from any other sounds. At some stage, however, it must treat speech sounds and nonspeech sounds differently, since we perceive them as different. The purpose of this study was to delimit the first location in the auditory pathway that makes this distinction using functional MRI, by identifying regions that are differentially sensitive to the internal structure of speech sounds as opposed to closely matched control sounds. We analyzed data from nine right-handed volunteers who were scanned while listening to natural and synthetic vowels, or to nonspeech stimuli matched to the vowel sounds in terms of their long-term energy and both their spectral and temporal profiles. The vowels produced more activation than nonspeech sounds in a bilateral region of the superior temporal sulcus, lateral and inferior to regions of auditory cortex that were activated by both vowels and nonspeech stimuli. The results suggest that the perception of vowel sounds is compatible with a hierarchical model of primate auditory processing in which early cortical stages of processing respond indiscriminately to speech and nonspeech sounds, and only higher regions, beyond anatomically defined auditory cortex, show selectivity for speech sounds.

Adult↗

The costs and benefits of tonal centers for chord processing.

Harmonic priming studies have shown that a musical context, with its established tonal center, influences target chord processing. This study investigated costs and benefits of priming tonal centers for target processing by adding a baseline condition (sequences without a specific tonal center). Results confirmed harmonic priming, with faster processing for related than for unrelated and less related targets (tonic chord, out-of-key chord, subdominant chord). Comparing targets in baseline contexts with targets in sequences with well-established tonal centers revealed a benefit of processing for related targets but a cost of processing for unrelated and less related targets. Findings are discussed in terns of tonal knowledge activation and suggest that an activated tonal center gives rise to strong expectations for the tonic.

Acoustic Stimulation↗

The role of melodic and temporal cues in perceiving musical meter.

A number of different cues allow listeners to perceive musical meter. Three experiments examined effects of melodic and temporal accents on perceived meter in excerpts from folk songs scored in 6/8 or 3/4 meter. Participants matched excerpts with 1 of 2 metrical drum accompaniments. Melodic accents included contour change, melodic leaps, registral extreme, melodic repetition, and harmonic rhythm. Two experiments with isochronous melodies showed that contour change and melodic repetition predicted judgments. For longer melodies in the 2nd experiment, variables predicted judgments best at the beginning of excerpts. The final experiment, with rhythmically varied melodies, showed that temporal accents, tempo, and contour change were the strongest predictors of meter. The authors' findings suggest that listeners combine multiple melodic and temporal features to perceive musical meter.

Adolescent↗

Low-frequency acoustic modulations generated by the high-frequency portion of the cochlea, noninvasively recorded from the scalp of mice (Mus musculus).

Vocalizations often contain low-frequency modulations of the envelope of a high-frequency sound. The high-frequency portion of the cochlear nerve of mice (Mus musculus) generates a robust phase-locked response to these low-frequency modulations, and it can be easily recorded from the surface of the scalp. The cochlea is most sensitive to envelope modulation frequencies of approximately 500 to 2000 Hz. These responses have detection thresholds that are approximately 10 dB more sensitive than auditory brainstem responses, and they are very sharply tuned. These measurements may provide a nontraumatic means of repeatedly assessing cochlear functions involved in sound localization and perception of vocalizations.

Animals↗

Fluid volume displacement at the oval and round windows with air and bone conduction stimulation.

The fluids in the cochlea are normally considered incompressible, and the fluid volume displacement of the oval window (OW) and the round window (RW) should be equal and of opposite phase. However, other channels, such as the cochlear and vestibular aqueducts, may affect the fluid flow. To test if the OW and RW fluid flows are equal and of opposite phase, the volume displacement was assessed by multiple point measurement at the windows with a laser Doppler vibrometer. This was done during air conduction (AC) stimulation in seven fresh human temporal bones, and with bone conduction (BC) stimulation in eight temporal bones and one human cadaver head. With AC stimulation, the average volume displacement of the two windows is within 3 dB, and the phase difference is close to 180 degrees for the frequency range 0.1 to 10 kHz. With BC stimulation, the average volume displacement difference between the two windows is greater: below 2 kHz, the volume displacement at the RW is 5 to 15 dB greater than at the OW and above 2 kHz more fluid is displaced at the OW. With BC stimulation, lesions at the OW caused only minor changes of the fluid flow at the RW.

Acoustic Stimulation↗

Postnatal development of physiological responses in auditory nerve fibers.

The discharges of auditory nerve fibers in kittens 4-37 days of age were recorded from micropipette electrodes. Tuning curves, thresholds, and the degree of tuning (Q 10) are compared over this age range. The tuning curves for fibers during the first postnatal week are relatively flat, with thresholds above 100 dB SPL. The response areas of VIII-nerve fibers during this period are restricted to low-to-middle frequencies. With increasing age there is a reduction in threshold and an increase in the sharpness of tuning which is dependent on fiber CF. Response characteristics similar to adult VIII-nerve fibers were observed first for fibers with CFs near 5 kHz. For the response measures used here, VIII-nerve fibers in kittens are adultlike by the third to fourth postnatal week. The results are discussed in relation to the morphological development of the cochlea reported by other investigators.

Aging↗

Interaural temporal discrimination using two sinusoidally amplitude-modulated, high-frequency tones: conditions of summation and interference.

This paper concerns sensitivity to interaural temporal delays (ITD) in the envelopes of two, sometimes simultaneously presented, sinusoidally amplitude-modulated (SAM) tones. The SAM tones were fully modulated (typically at a rate of 250 Hz) and had carrier frequencies of either 2 or 4 kHz. Of particular interest were cases in which the delay to be detected (target ITD) occurred in only one spectral region or in both. The reference ITD, to which the target ITD was added, was either 0, 300, or 600 microseconds. There were three general outcomes: (1) When both regions contained a target ITD, there was an improvement in sensitivity that was quantitatively consistent with an optimal use of independent information. This type of summation was seen even when the target ITDs were added to a pair of SAM tones with two different reference ITDs; (2) when the target ITD was restricted to the higher spectral region, sensitivity was reduced, indicating interference. Interference occurred when the two spectral regions had the same or different reference ITDs and the same or different rates of modulation; (3) sensitivity was unaffected (i.e., no interference occurred) when the target ITD was restricted to the lower spectral region of the pair of SAM tones. These results supplement the observations of Buell and Hafter [J. Acoust. Soc. Am. 90, 1894-1900 (1991)], who used low-frequency tones.

Acoustic Stimulation↗