A spectral-envelope synthesis model to study perceptual blend between wind instruments

Wind instrument sounds can be shown to be characterized by pitch-invariant spectral maxima or formants. An acoustical signal-analysis approach is pursued to obtain spectral-envelope descriptions that reveal these pitch- invariant spectral traits. Spectral envelopes are estimated empirically by applying a curve-fitting procedure to a composite distribution of partial-tone frequencies and amplitudes obtained across an instrument’s pitch range. A source-filter synthesis model is designed based on two independent formant filters with their frequency responses matched to the spectral envelope estimates. This is then used in perceptual experiments in which parameter variations of the synthesis filter are manipulated systematically to investigate their contribution to the degree of per- ceived blend between the synthesized sound and a recorded instrument sound. The perceptual relevance is assessed through two tasks in which participants either produce the best attainable blend by directly controlling synthesis parameters or rate the degree of blend for 5 parameter presets. Behavioral data from both experiments suggest the utility of this formant-based model for correlating pitch-invariant acoustical description with perceptual relevance, as both formant frequency and magnitude appear to affect perceived blend

Timbre blending of wind instruments: acoustics and perception

The acoustical and perceptual factors involved in timbre blending between orchestral wind instruments are investi- gated based on a pitch-invariant acoustical description of wind instruments. This description involves the estimation of spectral envelopes and identification of prominent spectral maxima or ‘formants’. A possible perceptual relevance for these formants is tested in two experiments employing differ- ent behavioral tasks. Relative frequency location and mag- nitude differences between formants can be shown to bear a pitch-invariant perceptual relevance to blend for several in- struments, with these findings contributing to a perceptual theory of orchestration

Timbre's function in the perception of affective intentions: Contextual information and effects of learning

Timbre has been identified by music perception scholars as a component in the communication of affect in music. While its function as a carrier of perceptually useful information about sound source mechanics has been established, less is understood about whether and how it functions as a carrier of information for communicating affect in music. To investigate these issues, listeners trained in Chinese and Western musical traditions were presented with phrases, measures, and individual notes of recorded excerpts interpreted with a variety of affective intentions by performers on instruments from the two cultures. These excerpts were analyzed to determine acoustic features that are correlated with timbre characteristics. Analysis revealed consistent use of temporal, spectral, and spectrotemporal attributes in judging affective intent in music, suggesting purposeful use of these properties within the sounds by listeners. Comparison between listeners' perceptions across notes and longer segments also revealed greater accuracy in perception with increased musical context. How timbre is used for musical communication appears to be implicated differently across musical traditions. The important role timbre plays also appears to vary for different positions within a musical phrase, suggesting that patterns of change over time are crucial in emotional communication

Loudness asymmetries for tones with increasing and decreasing levels

Presented at the 11th International Conference on Auditory Display (ICAD2005)Studies of loudness change for tones with linearly varying levels using different loudness rating methods, such as direct estimation or indirect estimation based on the start and end levels, have revealed an asymmetry depending on the direction of change (increasing vs decreasing). The present study examines loudness asymmetry between increasing and decreasing levels for 1-kHz tones over the range 60-80 dB SPL and over four ramp durations (2, 5, 10 and 20 s) using direct global and continuous loudness ratings made by subjects. Three measures extracted from continuous ratings (loudness duration, loudness change, loudness slope), on the one hand, and the global loudness rating, on the other hand are examined and analyzed separately. Measures extracted from continuous ratings do not reveal any significant perceptual asymmetry between an increasing and a decreasing ramp. However, direct estimation of the global loudness is higher for an increasing ramp than for a decreasing ramp. This result can be explained by a short-term auditory memory effect called the ``recency effect''

Blending between bassoon and horn players: an analysis of timbral adjustments during musical performance

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Achieving a blended timbre between two instruments is a common aim of orchestration. It relates to the auditory fusion of simultaneous sounds and can be linked to several acoustic factors (e.g., temporal synchrony, harmonicity, spectral relationships). Previous research has left unanswered if and how musicians control these factors during performance to achieve blend. For instance, timbral adjustments could be oriented towards the leading performer. In order to study such adjustments, pairs of one bassoon and one horn player participated in a performance experiment, which involved several musical and acoustical factors. Performances were evaluated through acoustic measures and behavioral ratings, investigating differences across performer roles as leaders or followers, unison or non-unison intervals, and earlier or later segments of performances. In addition, the acoustical influence of performance room and communication impairment were also investigated. Role assignments affected spectral adjustments in that musicians acting as followers adjusted toward a `darker' timbre, i.e., realized by reducing the frequencies of the main formant or spectral centroid. Notably, these adjustments occurred together with slight reductions in sound level, although this was more apparent for horn than bassoon players. Furthermore, coordination seemed more critical in unison performances and also improved over the course of a performance. These findings compare to similar dependencies found concerning how performers coordinate their timing and suggest that performer roles also determine the nature of adjustments necessary to achieve the common aim of a blended timbre

Perceptively based design of new car horn sounds

Proceedings of the 9th International Conference on Auditory Display (ICAD), Boston, MA, July 7-9, 2003.Due to the technologies used, there exist only a few different kinds of car horn sounds. We propose a method for the design of new sounds, based on a perceptual study of the actual sounds of car horns. Firstly we deal with recordings of existing car horns. We show that the different kinds of horn sounds can be divided into nine main families. Within these families we demonstrate secondly that the perception of timbre results from the integration of three elementary sensations. Thirdly, another experiment reveals that some sounds are better identified as car horns than others. A relationship between the perceived timbre of the sounds and their ability to be identified as car horns is established. Finally, we generalize our results to synthesized sounds. The synthesis method was designed to explore and enlarge the perceptual space. Studying these sounds confirms and generalizes the previous results. A model is proposed, which is able to synthesize sounds and predict their ability to be identified as car horns

Acoustical correlates of perceptual blend in timbre dyads and triads

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Achieving a blended timbre for particular combinations of instruments, pitches, and articulations is a common aim of orchestration. This involves a set of factors that this study jointly assesses by correlating the perceptual degree of blend with the underlying acoustical characteristics. Perceptual blend ratings from two experiments were considered, with the stimuli consisting of: 1)~dyads of wind instruments at unison and minor-third intervals and at two pitch levels, and 2)~triads of wind and string instruments, including bowed and plucked string excitation. The correlational analysis relied on partial least-squares regression, as this technique is not restricted by the number and collinearity of regressors. The regressors encompassed acoustical descriptors of timbre (spectral, temporal, and spectrotemporal) as well as ones accounting for pitch and articulation. From regressor loadings in principal-components space, the major regressors leading to substantial and orthogonal contributions were identified. The regression models explained around 90\% of the variance in the datasets, which was achievable with less than a third of all regressors considered initially. Blend seemed to be influenced by differences across intervals, pitch, and articulation. Unison intervals yielded more blend than did non-unison intervals, and the presence of plucked strings resulted in clearly lower blend ratings than for sustained instrument combinations. Furthermore, prominent spectral features of instrument combinations influenced perceived blend