Differences In Timbre Research Articles

VCM과 Beat Tracking을 이용한 음악의 명암 분류 기법 개발

Recently, a music genre classification has been studied. However, experts use different criteria to classify each of these classifications is difficult to derive accurate results. In addition, when the emergence of a new genre of music genre is a newly re-defined. Music as a genre rather than to separate search should be classified as emotional words. In this paper, the feelings of people on the basis of brightness and darkness tries to categorize music. The proposed classification system by applying VCM(Variance Considered Machines) is the contrast of the music. In this paper, we are using three kinds of musical characteristics. Based on surveys made throughout the learning, based on musical attributes(beat, timbre, note) was used to study in the VCM. VCM is classified by the trained compared with the results of the survey were analyzed. Note extraction using the MATLAB, sampled at regular intervals to share music via the FFT frequency analysis by the sector average is defined as representing the element extracted note by quantifying the height of the entire distribution was identified. Cumulative frequency distribution in the entire frequency rage, using the difference in Timbre and were quantified. VCM applied to these three characteristics with the experimental results by comparing the survey results to see the contrast of the music with a probability of 95.4% confirmed that the two separate.

Does timbre affect pitch?: Estimations by musicians and non-musicians

The present article focuses on the question of whether the timbre difference of two sounds with harmonic spectra, produced by natural musical instruments or the singing voice, may influence subjective assessments of the pitch of one sound in relation to the pitch of the other. The authors administered a series of perception tests to a group of professional musicians ( n = 13) and a group of non-musicians ( n = 13). The tests used the following pre-recorded sounds: the singing voice, the sound of the viola, and the sound of the trumpet. The participants had to compare the pitch of pair-wise presented successive tones and decide whether the second tone was either ‘flat’, ‘sharp’ or ‘in tune’. Tests using stimuli in the pitch range around A3 (220 Hz) at a loudness level of approximately 90 phons revealed pitch shifts of significant magnitude likely to affect intonation quality in a musical performance among both musicians and non-musicians. The conclusion drawn from the study is that timbre-induced pitch shifts may attain magnitudes that are likely to lead to conflicts between subjective and fundamental-frequency-based pitch assessments. Situations are described in which such conflicts may arise in actual musical practice.

Measuring timbre discrimination with cross-faded synthetic tones

The identification and discrimination of timbre are essential features of music perception. As timbre differences appear as multidimensional cues, the spectral shape, the spectral fluctuation, and the rise time are the most dominating parameters of timbre in normal-hearing listeners. We developed a psychoacoustical test to determine the timbre discrimination abilities using only the spectral difference as a cue. Therefore, a synthetically generated tone continuum was used in an adaptive alternative forced choice paradigm. The spectral difference was modified by cross-fading the tones adaptively, depending on the listeners’ response which allows very precise determinations of the just noticeable difference (JND). We measured the JND for the spectral difference with 18 normal-hearing listeners. The results confirm the applicability of the test to measure timbre discrimination with the spectral difference as solely cue. Further, the portability of the test to further dimensions of timbre is discussed.

Timbre change detection reflected by auditory evoked responses

Event Abstract Back to Event Timbre change detection reflected by auditory evoked responses Jaeho Seol1*, June S. Kim2 and Chun K. Chung2 1 Seoul National University, Interdisciplinary Programs in Cognitive Science, College of Humanities, South Korea 2 Seoul National University College of Medicine, MEG Center, Department of Neurosurgery, South Korea Distinguishing the timbre differences is essential to the auditory processing including human cognition such as language or music. The purpose of this study was to reveal how and when human brain detects the timbre change based on the acoustic phase modulation by sensory gating [1]. Four different frequencies (262, 523, 1047 and 2093 Hz, which corresponds to C4, C5, C6 and C7 in musical key, respectively, with a length of 50 ms, were combined into a mixture tone, with two different phases; 0 and π. Two different or same tones are presented through a conditioning-testing paradigm as a pair with an interval of 500 ms.Fourteen normal subjects participated. Subjects were instructed to discriminate whether two tones in a pair are identical or different during magnetoencephalography recording using a 306 channel whole head MEG system (Elekta NeuroMag VectorView). Auditory responses are identified as M50 and M100 equivalent current dipoles for two tones in a pair for all conditions. Gating is assessed by the comparison of auditory responses between the first (S1) and second (S2) stimulus in a pair, whereas physical discrimination is assessed by the S1 comparison among conditions. Both M50 and M100 magnitudes were different in terms of order (S1 vs. S2) in both same and different condition on the left hemisphere, which might reflect the gating out effect. On the right hemisphere, M50 responses of S1 were different from those of S2 only in the different conditions, which suggest the timbre change detection. These results might suggest the lateralization of the inhibitory process explained by gating effect and timbre detection process [2].

Enduring non-verbal memory for spectral timbre.

It is often assumed that auditory sensory memory disappears within a few seconds or is so smudged as not to permit fine discriminations between successive sounds beyond a few seconds. But studies have been confounded by proactive interference, task difficulty, and verbal labeling. In Experiment 1, participants heard two complex tones separated by a silent retention interval of 2, 4, 8, 16, or 32 s. Tones varied widely in pitch from trial to trial (so no standard memory could be formed) and were non-speech-like (difficult to verbalize), and very long inter-trial intervals were used (32 s) to reduce interference from prior sounds. After the tone-pair presentation, listeners made a same-different response based on slight differences in spectral timbre. Discrimination performance expressed as d′, at each retention interval revealed that the persistence of memory for spectral timbre surpassed the usually quoted lifetime of some few seconds and for certain participants it endured for 32 s. In Experiment 2, overall stimulus levels were roved within trials to rule out loudness cues in the discrimination. It is proposed that reasonably robust non-verbal memory traces for spectral timbre persist for several seconds allowing listeners to make fine discriminations of changes to a spectrum.

Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners

Normal-hearing (NH) listeners and hearing-impaired (HI) listeners detected and discriminated time-reversed harmonic complexes constructed of equal-amplitude harmonic components with fundamental frequencies (F0s) ranging from 50 to 800 Hz. Component starting phases were selected according to the positive and negative Schroeder-phase algorithms to produce within-period frequency sweeps with relatively flat temporal envelopes. Detection thresholds were not affected by component starting phases for either group of listeners. At presentation levels of 80 dB SPL, NH listeners could discriminate the two waveforms nearly perfectly when the F0s were less than 300-400 Hz but fell to chance performance for higher F0s. HI listeners performed significantly poorer, with reduced discrimination at several of the F0s. In contrast, at a lower presentation level meant to nearly equate sensation levels for the two groups, NH listeners' discrimination was poorer than HI listeners at most F0s. Roving presentation levels had little effect on performance by NH listeners but reduced performance by HI listeners. The differential impact of roving level suggests a weaker perception of timbre differences and a greater susceptibility to the detrimental effects of experimental uncertainty in HI listeners.

Parameter Estimation for Harmonic and Inharmonic Models by Using Timbre Feature Distributions

We describe an improved way of estimating parameters for an integrated weighted-mixture model consisting of both harmonic and inharmonic tone models. Our final goal is to build an instrument equalizer (music remixer) that enables a user to change the volume of parts of polyphonic sound mixtures. To realize the instrument equalizer, musical signals must be separated into each musical instrument part. We have developed a score-informed sound source separation method using the integrated model. A remaining but critical problem is to find a way to deal with timbre varieties caused by various performance styles and instrument bodies because our method used template sounds to represent their timbre. Template sounds are generated from a MIDI tone generator based on an aligned score. Difference of instrument bodies between mixed signals and template sounds causes timbre difference and decreases separation performance. To solve this problem, we train probabilistic distributions of timbre features using various sounds to reduce template dependency. By adding a new constraint of maximizing the likelihood of timbre features extracted from each tone model, we can estimate model parameters that express the timbre more accurately. Experimental results show that separation performance improved from 4.89 to 8.48dB.

What do male singers mean by modal and falsetto register? An investigation of the glottal voice source

The voice source differs between modal and falsetto registers, but singers often try to reduce the associated timbral differences, some even doubting that there are any. A total of 54 vowel sounds sung in falsetto and modal register by 13 male more or less experienced choir singers were analyzed by inverse filtering and electroglottography. Closed quotient, maximum flow declination rate, peak-to-peak airflow amplitude, normalized amplitude quotient, and level difference between the two lowest source spectrum partials were determined, and systematic differences were found in all singers, regardless of experience of singing. The observations seem compatible with previous observations of thicker vocal folds in modal register.

Effects of timbre and tempo change on memory for music

We investigated the effects of different encoding tasks and of manipulations of two supposedly surface parameters of music on implicit and explicit memory for tunes. In two experiments, participants were first asked to either categorize instrument or judge familiarity of 40 unfamiliar short tunes. Subsequently, participants were asked to give explicit and implicit memory ratings for a list of 80 tunes, which included 40 previously heard. Half of the 40 previously heard tunes differed in timbre (Experiment 1) or tempo (Experiment 2) in comparison with the first exposure. A third experiment compared similarity ratings of the tunes that varied in timbre or tempo. Analysis of variance (ANOVA) results suggest first that the encoding task made no difference for either memory mode. Secondly, timbre and tempo change both impaired explicit memory, whereas tempo change additionally made implicit tune recognition worse. Results are discussed in the context of implicit memory for nonsemantic materials and the possible differences in timbre and tempo in musical representations.

Musical Theater and Opera Singing—Why So Different? A Study of Subglottal Pressure, Voice Source, and Formant Frequency Characteristics

The considerable voice timbre differences between musical theater (MT) and western operatic singers are analyzed with respect to voice source and formant frequencies in five representatives of each singer group. Audio, subglottal pressure (P(sub)), and electroglottograph (EGG) signals were recorded while the subjects sang a sequence of [pae:] syllables starting at maximal vocal loudness and then gradually decreasing vocal loudness. The task was performed at each of two fundamental frequencies (F(0)), approximately one octave apart. Ten equally spaced P(sub) values were then selected for each F(0). The subsequent vowels were analyzed in terms of flow glottograms derived by inverse filtering the audio signal, which also yielded formant frequency data. Period time (T(0)), peak-to-peak pulse amplitude (U(p-t-p)), and maximum flow declination rate (MFDR) were measured from the flow glottograms while closed quotient Q(closed) (T(cl)/T(0)) was determined in combination with the differentiated EGG signal. Also the relationship between the first and the second harmonic in the spectrum (H(1)-H(2)), the amplitude quotient (AQ), that is, the ratio between U(p-t-p) and MFDR, and normalized AQ, that is, AQ normalized with respect to period time was calculated as well as the sound pressure level. The results showed that both the MT and the opera singers varied their P(sub) systematically, approximately doubling P(sub) for a doubling of F(0). For a given value of P(sub), the MT singers produced higher values of MFDR, U(p-t-p), and Q(closed), and lower values of H(1)-H(2), indicating a weaker fundamental. Further, the MT singers showed higher formant frequencies and did not show the opera singers' characteristic clustering of F(3), F(4), and F(5).

A non spectrum-based visual display tool

A software program was developed to help musicians learn to tune just intonation intervals. A reference tone is played and Lissajous-like figures present a visual representation of the interval the musician’s sound makes with the reference tone. This approach is interesting, because the musician receives coordinated aural and visual feedback in real time, and this visual representation is produced without the overhead of doing a Fourier transform. Experiments that modify the figures to produce a usable representation of timbral differences, also using a non spectrum-based algorithm, are planned. [Work supported by the Veneklasen Foundation.]

Sanguineti and Montale: Travelling Companions in the 1970s

This article considers parallels between Edoardo Sanguineti's collections of poems "Reisebilder" (1971) and "Postkarten" (1978) and Eugenio Montale's "Satura" (1971), notably their recording of the specifics of travel in a matter-of-fact, ironic, and quasi-diaristic style. While not suggesting any fundamental convergence between the two poets, the study none the less finds a widespread recurrence of images and scenarios which, combined with specific textual echoes, supports a hypothesis of influence. For all their differences in style, ideology, and timbre, Sanguineti draws on Montale's poetic persona and imagery in "Satura" for his own construction of a new literary model of the intellectual.

Perceptual acoustics of consonance and disssonance in multitimbral triads

Most studies of consonance and dissonance assume a singular spectrum for the constituent intervals of a dyad. Recently, the principal author conducted experiments evaluating triads consisting of digitally mixed combinations drawn from the MUMS single-note natural-instrument recordings. Results indicated that the main effect of ratings for consonance and dissonance correlated well with studies using artificial signals. However, interaction effects suggested perceptual differences related to the timbral differences across combinations. The present experiment evaluates perceptual and acoustical variables of the ten possible triadic combinations created with C4 as the lower and the ten with C5 as the upper notes. UCLA wind ensemble performers on oboe, flute, and clarinet, combinations designed to span timbral space, were digitally recorded. Analyses include perceptual ratings of consonance and dissonance, similarity, as well as acoustical analysis of roughness using a recently developed model. Since natural performances of any type vary in fundamental frequency, additional experiments will employ emulated oboe, flute, and clarinet (using the Kontakt Silver synthesizer in Sibelius 4) as well as purely synthetic stimuli, in order to ascertain the relationship of time-variant spectral properties to consonance, dissonance, and perceived similarity.

Modeling timbre distance with temporal statistics from polyphonic music

Timbre distance and similarity are expressions of the phenomenon that some music appears similar while other songs sound very different to us. The notion of genre is often used to categorize music, but songs from a single genre do not necessarily sound similar and vice versa. In this work, we analyze and compare a large amount of different audio features and psychoacoustic variants thereof for the purpose of modeling timbre distance. The sound of polyphonic music is commonly described by extracting audio features on short time windows during which the sound is assumed to be stationary. The resulting down sampled time series are aggregated to form a high-level feature vector describing the music. We generated high-level features by systematically applying static and temporal statistics for aggregation. The temporal structure of features in particular has previously been largely neglected. A novel supervised feature selection method is applied to the huge set of possible features. The distances of the selected feature correspond to timbre differences in music. The features show few redundancies and have high potential for explaining possible clusters. They outperform seven other previously proposed feature sets on several datasets with respect to the separation of the known groups of timbrally different music.

Repetition ‘‘pitch’’ in chinchillas

Repetition pitches are evoked in human listeners by rippled noises. Infinitely iterated rippled noise (IIRN) is generated when wideband noise is delayed, attenuated, and added to the original wideband noise through positive (+) or negative (−) feedback. In human listeners, the pitch of IIRN(+) is matched to the reciprocal of the delay, whereas the pitch of IIRN(−) is an octave lower. A stimulus generalization paradigm was used to characterize IIRN repetition pitch in chinchillas. Chinchillas were trained to discriminate IIRN(+) with a 4-ms delay from IIRN(+) with a 2-ms delay. In the generalization task, chinchillas were tested with IIRN(+) having delays between 2–4 ms. The pitches evoked by these IIRNs ranged from 500–250 Hz. The delayed noise attenuation for all IIRNs was fixed at −1 dB. A systematic gradient in behavioral response occurred along the dimension of delay for each animal tested, suggesting that a perceptual dimension of pitch exists. Responses to IIRN(−) evoking pitches between 500–250 Hz (delays of 1–2 ms) were also measured. Responses to IIRN(−) were more variable among animals, suggesting that other perceptual cues such as timbre differences may be stronger than the pitch cues. [Work supported by NIDCD R01 DC005596.]

Changes in emotional tone and instrumental timbre are reflected by the mismatch negativity

The present study examined whether or not the brain is capable to preattentively discriminate tones differing in emotional expression or instrumental timbre. In two event-related potential (ERP) experiments single tones (600 ms) were presented which had been rated as happy or sad in a pretest. In experiment 1, 12 non-musicians passively listened to tone series comprising a frequent (standard) single musical tone played by a violin in a certain pitch and with a certain emotional connotation (happy or sad). Among these standard tones deviant tones differing in emotional valence, either in instrumental timbre or in pitch were presented. All deviants generated mismatch negativity (MMN) responses. The MMN scalp topography was similar for all of the three deviants but latency was shorter for pitch deviants than for the other two conditions. The topography of the mismatch responses was indistinguishable. In a second experiment, subjects actively detected the deviant tones by button press. All detected deviants generated P3b waves at parietal leads. These results indicate that the brain is not only able to use simple physical differences such as pitch for rapid preattentive categorization but can also perform similar operations on the basis of more complex differences between tones of the same pitch such as instrumental timbre and the subtle timbral differences associated with different emotional expression. This rapid categorization may serve as a basis for the further fine-grained analysis of musical (and other) sounds with regard to their emotional content.

Auditory stream segregation relying on timbre involves left auditory cortex.

An important aspect of auditory scene analysis is sequential grouping of sounds that are similar to one another in preference to sounds that follow one another. This grouping problem is captured by stream segregation tasks with alternating distinct sounds. We examined human auditory cortex activity with low noise fMRI in a stream segregation experiment relying on timbre differences of alternating harmonic tones (organ-like and trumpet-like). We found that stream segregation performance in comparison to monitoring a non-separable control stream increased activation exclusively in left auditory cortex and particularly in posterior areas. Our results suggest that left auditory cortex is selectively involved in this complex sequential task although the available cue for sequential grouping was timbre, usually attributed to right hemisphere analysis.

The role of timbre in pitch matching abilities and pitch discrimination abilities with complex tones

Control of fundamental frequency (F0) is important for singing in-tune and is an important factor related to the perception of a talented singing voice. One purpose of the present study was to investigate the relationship between pitch-matching skills, which is one method of testing F0 control, and pitch discrimination skills. It was observed that there was a relationship between pitch matching abilities and pitch discrimination abilities. Those subjects that were accurate pitch matchers were also accurate pitch discriminators (and vice versa). Further, timbre differences appeared to play a role in pitch discrimination accuracy. A second part of the study investigated the effect of timbre on speech discrimination. To study this, all but the first five harmonics of complex tones with different timbre were removed for the pitch discrimination task, thus making the tones more similar in timbre. Under this condition no difference was found between the pitch discrimination abilities of those who were accurate pitch matchers and those who were inaccurate pitch matchers. The results suggest that accurate F0 control is at least partially dependent on pitch discrimination abilities, and timbre appears to play an important role in differences in pitch discrimination ability.

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.

Perception of relative formant amplitude for /i/ and /I/ in English

This work investigates listeners’ sensitivity to variations in the intensity of F2 and F4 for the English /i/-/I/ distinction using four-formant synthetic vowels. Two nine-step /i/-/I/ continua were synthesized with the amplitudes of F2 and F4 increasing or decreasing in steps of 2 dB. During 2AFC discrimination tasks, listeners were able to detect the 2-dB difference for both formants. /i/ was perceived as more natural with decreasing intensity of F2 and as less natural with increasing intensity of F2. The opposite was observed for /I/. Stepwise intensity changes of F4 were perceived as a difference in timbre for both vowels but not as a difference in naturalness. These data suggest that, perceptually, the patterns of relative formant amplitude provide information about the naturalness of /i/ and /I/ in English. The selective auditory sensitivity to the differential contribution of the intensities of F2 (variation in naturalness) and F4 (variation in timbre) is manifested when the 2-dB difference is detected for both frequency peaks. [Work supported by an INRS Award from NIH to R. Fox.]