A nonmusical paradigm for identifying absolute pitch possessors

The ability to identify and reproduce sounds of specific frequencies is remarkable and uncommon. The etiology and defining characteristics of this skill, absolute pitch (AP), have been very controversial. One theory suggests that AP requires a specific type of early musical training and that the ability to encode and remember tones depends on these learned musical associations. An alternate theory argues that AP may be strongly dependent on hereditary factors and relatively independent of musical experience. To date, it has been difficult to test these hypotheses because all previous paradigms for identifying AP have required subjects to employ knowledge of musical nomenclature. As such, these tests are insensitive to the possibility of discovering AP in either nonmusicians or musicians of non-Western training. Based on previous literature in pitch memory, a paradigm is presented that is intended to distinguish between AP possessors and nonpossessors independent of the subjects' musical experience. The efficacy of this method is then tested with 20 classically defined AP possessors and 22 nonpossessors. Data from these groups strongly support the validity of the paradigm. The use of a nonmusical paradigm to identify AP may facilitate research into many aspects of this phenomenon.     

Virtual pitch extraction from harmonic structures by absolute-pitch musicians

The ability of absolute-pitch (AP) musicians to identify or produce virtual pitch from harmonic structures without feedback or an external acoustic referent was examined in three experiments. Stimuli consisted of pure tones, missing-fundamental harmonic complexes, or piano notes highpass filtered to remove their fundamental frequency and lower harmonics. Results of Experiment I showed that relative to control (non-AP) musicians, AP subjects easily (>90%) identified pitch of harmonic complexes in a 12-alternative forced-choice task. Increasing harmonic order (i.e., lowest harmonic number in the complex), however, resulted in a monotonic decline in performance. Results suggest that AP musicians use two pitch cues from harmonic structures: 1) spectral spacing between harmonic components, and 2) octave-related cues to note identification in individually resolved harmonics. Results of Experiment II showed that highpass filtered piano notes are identified by AP subjects at better than 75% accuracy even when the note’s energy is confined to the 4th and higher harmonics. Identification of highpass piano notes also appears to be better than that expected from pure or complex tones, possibly due to contributions from familiar timbre cues to note identity. Results of Experiment III showed that AP subjects can adjust the spectral spacing between harmonics of a missing-fundamental complex to accurately match the expected spacing from a target musical note. Implications of these findings for mechanisms of AP encoding are discussed. The text was submitted by the authors in English.     

Cortical plasticity in an early blind musician: an fMRl study

Many studies have examined tactile perception and simple auditory perception in the blind, but none have previously investigated the neural basis of musical ability in this group. This topic is of particular interest because it has been suggested that early blind individuals may possess advanced musical skills (such as absolute pitch). Presumably, these skills could be the result of neural plasticity. It has been hard to empirically assess this claim because of the difficulty in recruiting an adequate number of subjects for use in a conventional paradigm. In the present paper, we report data from a congenitally blind musician, subject ML. Behavioral tests show that she possessed absolute pitch abilities that were similar to those of a reference group of AP musicians with normal vision. To examine the neural basis of her abilities we then tested subject ML and five control subjects using an fMRI paradigm. A regions-of-interest analysis found that similar areas (the right secondary auditory cortex, left IFG, left SMG) were activated in ML and the control subjects, to a similar degree, in response to music processing. However, ML showed additional activations in left parietal association cortices and extrastriate regions of the occipital lobe. Subject ML's data are consistent with a vast body of literature on blindness-induced plasticity. They extend these findings by demonstrating that cortical plasticity may underlie special musical skills as well. These data illustrate the potential value of case studies to investigate particularly rare phenotypes.     

Perceiving pitch absolutely: Comparing absolute and relative pitch possessors in a pitch memory task

Background  

The perceptual-cognitive mechanisms and neural correlates of Absolute Pitch (AP) are not fully understood. The aim of this fMRI study was to examine the neural network underlying AP using a pitch memory experiment and contrasting two groups of musicians with each other, those that have AP and those that do not.     

Pitch-interval discrimination and musical expertise: Is the semitone a perceptual boundary?

The ability to discriminate pitch changes (or intervals) is foundational for speech and music. In an auditory psychophysical experiment, musicians and non-musicians were tested with fixed- and roving-pitch discrimination tasks to investigate the effects of musical expertise on interval discrimination. The tasks were administered parametrically to assess performance across varying pitch distances between intervals. Both groups showed improvements in fixed-pitch interval discrimination as a function of increasing interval difference. Only musicians showed better roving-pitch interval discrimination as interval differences increased, suggesting that this task was too demanding for non-musicians. Musicians had better interval discrimination than non-musicians across most interval differences in both tasks. Interestingly, musicians exhibited improved interval discrimination starting at interval differences of 100 cents (a semitone in Western music), whereas non-musicians showed enhanced discrimination at interval differences exceeding 125 cents. Although exposure to Western music and speech may help establish a basic interval-discrimination threshold between 100 and 200 cents (intervals that occur often in Western languages and music), musical training presumably enhances auditory processing and reduces this threshold to a semitone. As musical expertise does not decrease this threshold beyond 100 cents, the semitone may represent a musical training-induced intervallic limit to acoustic processing.     

Discrimination of interval size in short tone sequences

This study investigates the discrimination of small changes of interval size in short sequences of musical tones. Major, minor and neutral thirds were varied in increments of 15 cents. The nine subjects had varying degrees of amateur musical experience-their level of musical training was lower than that of professional musicians. In some experiments the stimuli were presented purely melodically and in others they were presented together with a sustained tone at a higher pitch. Some subjects were able to make use of the additional cues from beats in the latter case. Category widths for identification were measured at around 70 cents and just-noticeable differences in frequency were measured at around 10 cents. Little significant variation of inter-stimulus sensitivity index d' was observed across the stimulus sets, i.e., there was little evidence for "anchors" or "landmarks" within the range of tunings employed. However, for major thirds, discrimination of the 15 cent increment between 400 and 415 cents was reduced compared to discrimination of other 15 cent increments within the stimulus sets.     

Perception of musical and lexical tones by Taiwanese-speaking musicians

This study explored the relationship between music and speech by examining absolute pitch and lexical tone perception. Taiwanese-speaking musicians were asked to identify musical tones without a reference pitch and multispeaker Taiwanese level tones without acoustic cues typically present for speaker normalization. The results showed that a high percentage of the participants (65% with an exact match required and 81% with one-semitone errors allowed) possessed absolute pitch, as measured by the musical tone identification task. A negative correlation was found between occurrence of absolute pitch and age of onset of musical training, suggesting that the acquisition of absolute pitch resembles the acquisition of speech. The participants were able to identify multispeaker Taiwanese level tones with above-chance accuracy, even though the acoustic cues typically present for speaker normalization were not available in the stimuli. No correlations were found between the performance in musical tone identification and the performance in Taiwanese tone identification. Potential reasons for the lack of association between the two tasks are discussed.     

Pitch-Synchronous Changes in the Anterior Cricothyroid Space During Singing

Pitch-synchronous changes in the anterior cricothyroid (CT) space were registered with ultrasonography (USG) for ten healthy subjects (5 males, 5 females) during the production of musical fifths throughout the whole voice range. One of the males and one of the females were trained amateur singers, the other subjects were choir singers. The average decrease in CT space per a musical fifth was 1.3-2.4 mm for the males and 1.0-1.8 mm for the females; the average decrease was smaller in the middle of the pitch range for both genders. The results suggest that (1) USG can be used for detection of pitch-synchronous changes in the CT space; (2) these changes are dependent on pitch range; and (3) more trained singers tend to have somewhat smaller changes than less trained subjects at certain frequencies. The results seem to indicate that F0 control mechanism varies according to pitch range and register, and possibly according to individual structure and vocal technique related differences.     

Categorical perception--phenomenon or epiphenomenon: evidence from experiments in the perception of melodic musical intervals

Categorical perception was investigated in a series of experiments on the perception of melodic musical intervals (sequential frequency ratios). When procedures equivalent to those typically used in speech-perception experiments were employed, i.e., determination of identification and discrimination functions for stimuli separated by equal physical increments), musical intervals were perceived categorically by trained musicians. When a variable-step-size (adaptive) discrimination procedure was used, evidence of categorical perception (in the form of smaller interval-width DL's for ratios at identification category boundaries than for ratios within categories), although present initially, largely disappeared after subjects had reached asymptotic performance. However, equal-step-size discrimination functions obtained after observers had reached asymptotic performance in the adaptive paradigm were not substantially different from those initially obtained. The results of other experiments imply that this dependence of categorical perception on procedure may be related to differences in stimulus uncertainty between the procedures. An experiment on the perception of melodic intervals by musically untrained observers showed no evidence for the existence of "natural" categories for musical intervals.     

Musical pitch of two-tone complexes and predictions by modern pitch theories.

Most studies of the musical pitch of harmonic tone complexes have utilized signals comparing two or more successive harmonics. The present study provides systematic data on melodic interval recognition by three musically experienced subjects with sounds whose missing fundamentals were represented by two nonsuccessive harmonics nf0,(n + m)f0, delivered to separate ears. Data were obtained in the ranges 1 less than or equal to n less than or equal to 9, 2 less than or equal to m less than or equal to 4, and 200 Hz less than or equal to f0 less than or equal to 1000 Hz. The data are interpreted in the light of three theories, the "optimum processor theory," the "virtual pitch theory," and the "pattern transformation theory." For each theory, a constraint on preformance is proposed based on interference between the "analytic" and "synthetic" pitch perception modes. The former is obtained with large spacings between harmonics, where listeners are more likely to perceive harmonics as individual tones, each having their own pitch. This degrades the listener's ability to hear the fundamental pitch.     

Effects of stimulus frequency and complexity on the mismatch negativity and other components of the cortical auditory-evoked potential

This study investigated, first, the effect of stimulus frequency on mismatch negativity (MMN), N1, and P2 components of the cortical auditory event-related potential (ERP) evoked during passive listening to an oddball sequence. The hypothesis was that these components would show frequency-related changes, reflected in their latency and magnitude. Second, the effect of stimulus complexity on those same ERPs was investigated using words and consonant-vowel tokens (CVs) discriminated on the basis of formant change. Twelve normally hearing listeners were tested with tone bursts in the speech frequency range (400/440, 1,500/1,650, and 3,000/3,300 Hz), words (/baed/ vs /daed/) and CVs (/bae/ vs /dae/). N1 amplitude and latency decreased as frequency increased. P2 amplitude, but not latency, decreased as frequency increased. Frequency-related changes in MMN were similar to those for N1, resulting in a larger MMN area to low frequency contrasts. N1 amplitude and latency for speech sounds were similar to those found for low tones but MMN had a smaller area. Overall, MMN was present in 46%-71% of tests for tone contrasts but for only 25%-32% of speech contrasts. The magnitude of N1 and MMN for tones appear to be closely related, and both reflect the tonotopicity of the auditory cortex.     

The dependency of timbre on fundamental frequency

The dependency of the timbre of musical sounds on their fundamental frequency (F0) was examined in three experiments. In experiment I subjects compared the timbres of stimuli produced by a set of 12 musical instruments with equal F0, duration, and loudness. There were three sessions, each at a different F0. In experiment II the same stimuli were rearranged in pairs, each with the same difference in F0, and subjects had to ignore the constant difference in pitch. In experiment III, instruments were paired both with and without an F0 difference within the same session, and subjects had to ignore the variable differences in pitch. Experiment I yielded dissimilarity matrices that were similar at different F0's, suggesting that instruments kept their relative positions within timbre space. Experiment II found that subjects were able to ignore the salient pitch difference while rating timbre dissimilarity. Dissimilarity matrices were symmetrical, suggesting further that the absolute displacement of the set of instruments within timbre space was small. Experiment III extended this result to the case where the pitch difference varied from trial to trial. Multidimensional scaling (MDS) of dissimilarity scores produced solutions (timbre spaces) that varied little across conditions and experiments. MDS solutions were used to test the validity of signal-based predictors of timbre, and in particular their stability as a function of F0. Taken together, the results suggest that timbre differences are perceived independently from differences of pitch, at least for F0 differences smaller than an octave. Timbre differences can be measured between stimuli with different F0's.     

语后聋人工耳蜗使用者电刺激听觉部位音调感知研究

系统地研究了人工耳蜗植入者的电刺激听觉部位音调感知,全面地探讨了部位音调感知与人工耳蜗植入者言语识别和音乐感知的关系。4位成人语后聋人工耳蜗植入者参与了该研究。通过电极音调排序测试度量植入者的部位音调感知能力。言语能力测试和音乐音高分辨测试分别用米考察植入者的言语识别和音乐感知能力。结果显示,随着电极刺激部位从蜗尖移向蜗底,所有受试者均可获得从"低"到"高"的音调感知变化,但个体差异较大。受试者的言语识别结果与其电刺激听觉部位音调感知能力相关,但受到天花板效应影响,对应关系并不明显。受试者的音乐音高分辨成绩与其电刺激听觉部位音调感知能力呈较好的对应关系。结果表明,当前人工耳蜗声音编码策略所传递的声信号特征已可使植入者获得良好的言语识别效果;且安静环境下言语识别对植入者的部位音调感知能力要求不高。但当前的声音编码策略并未能有效对音乐信号进行编码;植入者在理解音乐这类复杂声信号时,其电刺激听觉部位音调感知能力一定程度决定了其听音效果。      

Absolute pitch correlates with high performance on interval naming tasks

Absolute pitch, the rare ability to identify or produce a musical tone without a reference tone, has been shown to be advantageous in some musical tasks; however, its relevance in musical contexts primarily involving relative pitch has been questioned. To explore this issue, 36 trained musicians-18 absolute pitch possessors and 18 non-possessors with equivalent age of onset and duration of musical training-were tested on interval naming tasks requiring only relative pitch. The intervals to be named were either ascending or descending with separation ranging from 1 to 12 semitones and equally involved all 12 pitch classes. Three different conditions were employed; these used brief sine waves, piano tones, and piano tones preceded by a V7-I chord cadence so as to establish a tonal context. The possession of absolute pitch was strongly correlated with enhanced performance on all these tests of relative pitch. Furthermore, no evidence was found that this absolute pitch avantage depended on key, interval size, or musical context.     

Auditory-nerve responses predict pitch attributes related to musical consonance-dissonance for normal and impaired hearing

Human listeners prefer consonant over dissonant musical intervals and the perceived contrast between these classes is reduced with cochlear hearing loss. Population-level activity of normal and impaired model auditory-nerve (AN) fibers was examined to determine (1) if peripheral auditory neurons exhibit correlates of consonance and dissonance and (2) if the reduced perceptual difference between these qualities observed for hearing-impaired listeners can be explained by impaired AN responses. In addition, acoustical correlates of consonance-dissonance were also explored including periodicity and roughness. Among the chromatic pitch combinations of music, consonant intervals/chords yielded more robust neural pitch-salience magnitudes (determined by harmonicity/periodicity) than dissonant intervals/chords. In addition, AN pitch-salience magnitudes correctly predicted the ordering of hierarchical pitch and chordal sonorities described by Western music theory. Cochlear hearing impairment compressed pitch salience estimates between consonant and dissonant pitch relationships. The reduction in contrast of neural responses following cochlear hearing loss may explain the inability of hearing-impaired listeners to distinguish musical qualia as clearly as normal-hearing individuals. Of the neural and acoustic correlates explored, AN pitch salience was the best predictor of behavioral data. Results ultimately show that basic pitch relationships governing music are already present in initial stages of neural processing at the AN level.     

Place-pitch perception in electrical hearing with post-lingually deafened cochlear implant users

The main goal of this study was to systematically investigate place-pitch perception in electrical hearing and the relative relationship between place-pitch perception ability,speech understanding and musical pitch discrimination by cochlear implant(CI) users.Electrode pitch ranking test was carried out to evaluate the place-pitch perception ability of CI users. Four post-lingually deafened CI users were recruited.They also participated in the speech recognition test and musical pitch discrimination test.Results showed that place pitch were generally ordered from apical to basal electrodes.The apical electrodes were judged lower in pitch than basal electrodes.Large individual difference was found.Comparing pitch and speech performance,the speech recognition result was related to the place-pitch perception ability of CI users,but this relationship was limited by the ceiling effects.However,a correlative relationship was found between musical pitch discrimination result and place-pitch ability of CI users.It indicated that the current signal processing of CI system can provide sufficient information for speech understanding but not for music perception of CI users.To a certain extent,music perception of CI users was determined by their place-pitch abilities.     

频域分辨率和时域包络周期性对音乐音高分辨的影响

系统地分析与探讨频域分辨率及时域包络周期性对不同音色及频率覆盖范围的音乐音高分辨的影响。选择钢琴、小提琴、小号及单簧管四种乐器的乐音和特定的复合音作为测试音源。利用噪声调制的声码器模型调控音乐信号的频域分辨率和时域包络周期性。十位正常听力者参与了该项音高分辨测试。实验结果表明,随着频域分辨率的提高,受试者对音高分辨的准确率呈上升趋势,16个频带已可获得较好的音高分辨效果;当时域包络周期性信息增加时,未见其对音高分辨产生一致性积极影响。      

Effects of spectral resolution and temporal envelope periodicity to musical pitch discrimination

The main goal of this study was to systematically investigate the relative contribution of spectral resolution and temporal envelope periodicity to musical pitch discrimination. Stimuli from four instruments(clarinet,trumpet,piano and violin) and synthetic complex tone were utilized.A noise-excited vocoder was used to control the spectral resolution and temporal envelope periodicity of the musical stimuli.Ten normal-hearing subjects were recruited for the study.Psychoacoustic experiments on pitch discrimination were carried out.Results showed that the spectral cue was important for musical pitch discrimination.Relative good performance could be achieved when there were 16 frequency channels.No clear effect was found for the temporal envelope periodicity to pitch discrimination.     

The influence of musical training on the perception of sequentially presented mistuned harmonics

The question of whether musical scales have developed from a processing advantage for frequency ratios based on small integers, i.e., ratios derived from relationships among harmonically related tones, is widely debated in musicology and music perception. In the extreme position, this processing advantage for these so-called "natural intervals" is assumed to be inherent, and to apply to sequentially presented tones. If this is the case, evidence for this processing advantage should show up in psychoacoustic experiments using listeners from the general population. This paper reports on replications and extensions of two studies from the literature. One [Lee and Green, J. Acoust. Soc. Am. 96, 716-725 (1994)] suggests that listeners from the general population can in fact determine whether sequentially presented tones are harmonically related. The other study [Houtgast, J. Acoust. Soc. Am. 60, 405-409 (1976)] is interpreted in different terms, but could be confounded by such an ability. The results of the replications and extensions, using listeners of known relative pitch proficiency, are consistent with the idea that only trained musicians can reliably determine whether sequentially presented tones are harmonically related.     

Temporal pitch perception at high rates in cochlear implants

A recent study reported that a group of Med-El COMBI 40+CI (cochlear implant) users could, in a forced-choice task, detect changes in the rate of a pulse train for rates higher than the 300 pps "upper limit" commonly reported in the literature [Kong, Y.-Y., et al. (2009). J. Acoust. Soc. Am. 125, 1649-1657]. The present study further investigated the upper limit of temporal pitch in the same group of CI users on three tasks [pitch ranking, rate discrimination, and multidimensional scaling (MDS)]. The patterns of results were consistent across the three tasks and all subjects could follow rate changes above 300 pps. Two subjects showed exceptional ability to follow temporal pitch change up to about 900 pps. Results from the MDS study indicated that, for the two listeners tested, changes in pulse rate over the range of 500-840 pps were perceived along a perceptual dimension that was orthogonal to the place of excitation. Some subjects showed a temporal pitch reversal at rates beyond their upper limit of pitch and some showed a reversal within a small range of rates below the upper limit. These results are discussed in relation to the possible neural bases for temporal pitch processing at high rates.