Timbre plays an essential role in transmitting musical affect, and in recent years, our understanding of emotional expression in music has been enriched by contributions from the burgeoning field of embodied music cognition. However, little attention has been paid to timbre as a possible mediator between musical embodiment and affect. In three experiments, we investigated the embodied dimensions of timbre perception by focusing on timbral qualities considered “noisy” and aversive. In Experiment 1, participants rated brief isolated natural timbres scaled into ordinal levels of “noisiness.” Experiment 2 employed the same design with a focus on polyphonic timbre, using brief (400 ms) excerpts from 6 popular music genres as stimuli. In Experiment 3, functional magnetic resonance imaging was used to explore neural activations associated with perception of stimuli from Experiment 1. Converging results from behavioral, acoustical, and fMRI data suggest a motor component to timbre processing, particularly timbral qualities considered “noisy,” indicating a possible enactive mechanism in timbre processing. Activity in somatomotor areas, insula, and the limbic system increased the more participants disliked a timbre, and connectivity between the premotor cortex and insula relay decreased. Implications for recent theories of embodied music cognition, affect, and timbre semantics are discussed in conclusion.

Four experiments were conducted to explore the timbres of natural, continuant orchestral instruments with emulation based on sampling, frequency modulation ( FM) synthesis, and a hybrid consisting of sampling and synthesis techniques combined. Identification of instruments using verbal labels was significantly better for the natural and sampling- based signals than for either FM synthesis or the hybrid technique, a result also found for aural categorization. Perceptual scaling of timbral similarities demonstrated great consistency across a series of independent variables, including musical training, monophonic and stereo presentation, and long versus short signal durations. The first dimension of the classical multidimensional scaling (CMDS) solutions mapped onto long- time- average spectral centroid. The second dimension mapped onto a measure of spectral variability. Little evidence was found for the mapping of attack time or signal duration onto either dimension. A third dimension separated most natural instruments from their emulated counterparts. Experiments using verbal attribute ratings confirmed the correlation of spectral centroid, the first dimension of the perceptual space, and ratings of nasality; the second dimension correlated with spectral variability and modestly correlated with ratings of rich, brilliant, and tremulous. Mismatches of spectral distribution and variability resulted in poor emulations of the natural instruments. Results suggest that further study of centroid and time-variant psychophysical properties is warranted.

A study on the verbal attributes of timbre was conducted in an effort to interpret the dimensional configuration of the similarity spaces of simultaneously sounding wind instrument timbres. In the first experiment, subjects rated 10 wind instrument dyads on eight factorially pure semantic differentials from von Bismarck's (1974a) experiments. Results showed that the semantic differentials failed to differentiate among the 10 timbres. The semantic differential methodology was changed to verbal attribute magnitude estimation (VAME), in which a timbre is assigned an amount of a given attribute. This procedure resulted in better differentiation among the 10 timbres, the first factor including attributes such as heavy, hard, and loud, the second factor involving sharp and complex, a contrast with von Bismarck's results. Results of the VAME analysis separated alto saxophone dyads from all others, but mapped only moderately well onto the perceptual similarity spaces. It was suggested that many of the von Bismarck adjectives lacked ecological validity.

Experiments were conducted to explore the relationship between wind instrument dyad timbres and verbal attributes drawn from the musicological literature in order to compare and contrast results with studies using artificial stimuli and amusical rating scales. In the first experiment, all adjectives in Piston's (1955) "Orchestration" were collated and subsequently reduced to 61 examples. A checklist procedure was used in response to the dyad timbres to further reduce the set of adjectives to 21. The 21 adjectives were used in verbal attribute magnitude estimation of the 10 wind instrument dyad timbres. Principal components analysis of ratings revealed four verbal attribute factors, accounting for 90.604% of the variance: power, strident, plangent, and reed. Correlational analyses demonstrated an improvement in mapping between the ratings and perceptual similarity spaces over the procedure used in Part I of this study. The two-dimensional timbral circumplex was interpreted as having a principal dimension of nasality versus richness and a secondary dimension of reediness versus brilliance.

Timbral similarities among wind instrument duos were studied. Flute, oboe, E♭ alto saxophone, B♭ clarinet, and B♭ trumpet instrumentalists performed in all possible duo pairings (dyads). Source material included B♭4 unisons, unison melody, major thirds, and harmonized melody. Nonunison combinations had each instrument of the pair as the soprano, creating a total of six contexts. Music major and nonmusic major subjects rated the similarity of all possible pairs of dyads in each of the six contexts. Classical multidimensional scaling (MDS) was performed; contexts were treated as " subjects" in an individual differences scaling (INDSCAL) analysis of composite data. The resulting spaces had two stable, interpretable dimensions. From verbal attribute rating experiments ( Kendall & Carterette, in preparation, a), these were identified as " nasal" vs. " not nasal," and " rich" vs. " brilliant." A third dimension was interpreted as "simple" vs. "complex."Extrema in the space were associated with three of the five instruments: Trumpet (brilliant), saxophone (rich), and oboe ( nasal). Data that were amalgamated over contexts and plotted in two dimensions yielded a circumplicial configuration. Implications for orchestration are discussed and a theoretical model of timbre combinations and groupings is presented.

This study focuses on the performer-listener link of the chain of musical communication. Using different perceptual methods (categorization, matching, and rating), as well as acoustical analyses of timing and amplitude, we found that both musicians and nonmusicians could discern among the levels of expressive intent of violin, trumpet, clarinet, oboe, and piano performers. Time-contour profiles showed distinct signatures between instruments and across expressive levels, which affords a basis for perceptual discrimination. For example, for "appropriate" expressive performances, a gradual lengthening of successive durations leads to the cadence. Although synthesized versions based on performance timings led to less response accuracy than did the complete natural performance, evidence suggests that timing may be more salient as a perceptual cue than amplitude. We outline a metabolic communication theory of musical expression that is based on a system of sequences of states, and changes of state, which fill gaps of inexorable time. We assume that musical states have a flexible, topologically deformable nature. Our conception allows for hierarchies and structure in active music processing that static generative grammars do not. This theory is supported by the data, in which patterns of timings and amplitudes differed among and between instruments and levels of expression.

An experiment was designed to assess the relative contribution to listener categorization strategies of various temporal partitions of the acoustic signal for trumpet, clarinet, and violin. The role of context, whole phrase versus single note, was also evaluated. Analog recordings of three folk-song phrases performed on two clarinets, violins, and trumpets were digitized. A computer program was developed for digital signal editing. Signal edit conditions included normal, time-variant steady-state alone, transients alone, and static steady state with and without transients. Musicians and nonmusicians responded to a matching procedure in which unedited signals of one phrase were choice stimuli and edited signals for two different phrases served as models. Two replications of all possible combinations of instrument, phrase, and edit conditions were presented for a total of 72 items. Two additional groups of musicians and nonmusicians participated in an identical procedure in which the stimuli were single notes extracted from two phrases. Analyses revealed that, for the whole-phrase signals, there was no case in which the means obtained with the "normal" signal and the "time variant steady state alone" signal were statistically different; these means were always statistically higher than the "transients alone" mean. It was concluded that transients were neither sufficient nor necessary for the categorization of trumpet, clarinet, and violin in whole-phrase contexts. The time- variant quasi-steady state was sufficient and necessary for the categorization of trumpet and violin phrases, and it was sufficient but not necessary for the categorization of clarinet phrases. For the single- note stimuli, "transients alone" yielded means statistically equivalent to the "normal" and "time variant steady state alone" means. It was concluded that transients were sufficient, but not necessary, for instrument categorization in single-note contexts. The whole-phrase context yielded significantly higher means than the single-note context; music majors performed the task with greater accuracy than nonmusic majors.