Multidimensional Perceptual Space Research Articles

Understanding the Perceptual Spectrum of Commercial Perfumes as a Basis for a Standard Sensory Wheel of Fragrances

Given the enormous number of perfumes available on the market, it is of interest to guide consumers in their purchase of a new fragrance. One approach is to project the multidimensional perceptual space of scents on a two-dimensional sensory map based on meaningful dimensions. One of the pioneering studies on this issue mapped 94 commercial perfumes according to two axes. Such an odor map is discussed here in detail by applying Principal Component Analysis to the numeric odor description of 176 fragrances. Quantitative odor profiles were obtained from Fragrantica’s website and three fragrances guides published by Haarmann & Reimer, Michael Edwards, and the French Society of Perfumers. A sensory map was obtained that reflected the similarities and dissimilarities between those odor descriptors most commonly used in perfumery. This representation was consistent with other related plots that have been previously reported. One dimension discriminated between fragrances targeted at men versus women. An orthogonal factor distinguished perfumes for daytime versus nighttime wear. These ratings, as well as seasonal preferences, could be estimated based on the main odor character attributes applied to describe the scent. The results provide a scientific basis for the comprehensive classification of commercial perfumes compiled by Edwards according to his famous “Fragrance Wheel”.

Analysis on paralinguistic prosody control in perceptual impression space using multiple dimensional scaling

A multi-dimensional perceptual space for communicative speech prosodies was derived using a psychometric method from multi-dimensional expressions of impressions to characterize paralinguistic information conveyed by prosody in communication. Single word utterances of “n” were employed to allow freedom from lexical effects and to cover communicative prosodic variations as much as possible. The analysis of daily conversations showed that conversational speech impressions were manifested in the global F0 control of “n” as differences of average height (high–low) and dynamic patterns (rise, fall, gradual fall, and rise&fall). Using controlled single utterances of “n”, multiple dimensional scaling analysis was applied to a mutual distance matrix obtained by 26 dimensional vectors expressing perceptual impressions. The result showed the three-dimensional structure of a perceptual impression space, and each dimension corresponded to different F0 control characteristics. The positive–negative impression can be controlled by average F0 height while confident–doubtful or allowable–unacceptable impressions can be controlled by F0 dynamic patterns. Unlike conventional categorical classification of prosodic patterns frequently observed in studies of emotional prosody, this control characterization enables us to flexibly and quantitatively describe prosodic impressions. These experimental results allow the possibility of input specifications for communicative prosody generation using impression vectors and control through average F0 height and F0 dynamic patterns. Instead of the generation of speech with categorical prototypical prosody, more adequate communicative speech synthesis can be approached through input specification and its correspondence with control characteristics.

Using electropalatographic feedback to treat the speech of a child with severe-to-profound hearing loss.

Abstract The speech production of a 7-year-old child with severe-to-profound hearing loss and severe speech disorder was treated using visual feedback via electropalatography (EPG). The child's productions of /k/ and /t/ were treated in consonant-vowel syllables in three vowel contexts. A single-subject multiple-baseline design was used to document treatment effects and generalization. Visual inspection and multiple time-series analyses were used to assess the data. The child demonstrated a treatment effect for /k/ as measured by lingual-palatal placement and perceptual adequacy of the productions. A treatment effect for /t/ also was suggested. Generalization was observed for the production of /g/ at the syllable level, and /g/ and /k/ in monosyllabic words in the word-initial position. Generalization to other sounds and word-final positions was not evidenced. Of note was the extreme performance variability associated with the treatment. Key Words: Electropalatography, Speech Treatment, Hearing Loss, Children. Introduction The ability to develop the motor and linguistic skills for the normal production of speech typically requires a relatively intact auditory system. Audition is critical for the development of a linguistic system with its phonological performance rules and associated acoustic goals (Tye-Murray, 1992). Furthermore, recent auditory-based models of speech development and production argue that a multi-dimensional auditory perceptual space emerges during infancy and provides the basis for the development and maintenance of speech (Callan, Kent, Guenther, & Vorperian, 2000; Guenther, 1995; Perkell et al., 1995, 1997). Speech production is learned by mapping the orosensory information to acoustic-based targets (or regions) within this auditory space. So, speech impairment and reduced speech intelligibility are expected consequences of prelingual hearing loss if early and substantive intervention does not occur (Hudgins & Numbers, 1942; Smith, 1975; Yoshinaga-Itano & Sedey, 1998). Most children with hearing loss require some type of intervention if they are to speak intelligibly and in a manner acceptable to normal hearing listeners, even though the character and severity of the speech impairments vary greatly across children. Much of the variability relates to the severity of their hearing impairment, but even children with mild-to-moderate hearing loss are at risk for resonance and segmental speech problems (Elfenbein, Hardin-Jones, & Davis, 1994; Oller & Kelly, 1974; West & Weber, 1973). The speech differences of children with mild-to-moderate hearing loss typically are treated in the same manner as the speech of hearing children, but children with more severe hearing loss tend to require more aggressive and long-term treatment to become effective oral-aural communicators. Despite the acknowledged long-term need, well-controlled studies documenting speech treatment effectiveness and efficacy is limited for this population. Even in the growing cochlear implant literature, little has been reported on what behavioral treatment approaches work best with the various types of speech impairments that occur secondary to hearing loss in children. Nearly all treatment approaches applied to children with hearing loss try to stimulate optimal use of residual hearing and/or compensate for the hearing loss by developing alternate routes for input and feedback (see Pratt, 2005 and Pratt & Tye-Murray, 1997 for reviews). Implementing speech treatment through the auditory modality typically is preferred if the auditory system itself can be treated (i.e., sensory devices and auditory training) so that sufficient sensory input and feedback are accessible. However, if hearing is limited and children are unable to form or interface with a complete internal auditory mapping of the auditory space, speech production will be restricted. Furthermore, there remain a substantive number of children with hearing loss who fail to develop normal speech production and phonology skills despite appropriate and early fitting of sensory devices and adequate behavioral intervention (Blamey et al. …

Characterizing the sound quality of air-conditioning noise*1

The aim of the psychoacoustic study presented here was to characterize listeners' preferences for a set of sounds produced by different brands and models of indoor air-conditioning units. In addition, some synthetic sounds, created by interpolation between recorded sound samples, were integrated into the set. The multidimensional perceptual space and the corresponding physical space representative of the sound set were determined with multidimensional scaling (MDS). Then the preferences for different classes of listeners were related to the physical space. The best spatial model yielded by the MDS had three common dimensions and specificities. The three dimensions are correlated with the ratio of the noisy part of the spectrum to the harmonic part (NHR), with the spectral center of gravity (SC) and with loudness ( N ). Two classes of listeners can be distinguished in terms of preference. For one, preference varied primarily with loudness, whereas for the other it varied more with SC and NHR. However, for one class the preference grew with the parameter NHR, while it decreased for the other class. The results replicate under different laboratory conditions and indicate the usefulness of this sound quality assessment approach for characterizing appliance noises.

Characterizing the sound quality of air-conditioning noise

The aim of the psychoacoustic study presented here was to characterize listeners' preferences for a set of sounds produced by different brands and models of indoor air-conditioning units. In addition, some synthetic sounds, created by interpolation between recorded sound samples, were integrated into the set. The multidimensional perceptual space and the corresponding physical space representative of the sound set were determined with multidimensional scaling (MDS). Then the preferences for different classes of listeners were related to the physical space. The best spatial model yielded by the MDS had three common dimensions and specificities. The three dimensions are correlated with the ratio of the noisy part of the spectrum to the harmonic part (NHR), with the spectral center of gravity (SC) and with loudness ( N). Two classes of listeners can be distinguished in terms of preference. For one, preference varied primarily with loudness, whereas for the other it varied more with SC and NHR. However, for one class the preference grew with the parameter NHR, while it decreased for the other class. The results replicate under different laboratory conditions and indicate the usefulness of this sound quality assessment approach for characterizing appliance noises.

PERCEPTUAL ATTRIBUTES OF MUSICAL TIMBRE FOR CONTROLLING EFFECTS PROCESSING

A psychophysical investigation of timbre was undertaken with the intent of deriving quantitative results that could be useful in developing a better human interface to control effects processing for expressiveness in music. Multidimensional perceptual scaling analysis was performed for a set of musical timbres. Two listening experiments were performed in order to determine the most salient perceptual attributes. These two experiments provide data enabling KANSEI engineering for these effects. A commercially available effects processor generated the six stimuli used in these experiments. In the first experiment, listeners were asked to give ratings of the relative difference between two stimuli without regard to any property contributing to that difference. In the second experiment, the listeners were asked to give ratings of each stimulus with respect to a particular property. Dissimilarity ratings of all pair-wise comparisons of the six effects were submitted to INdividual Differences SCALing (INDSCAL) analysis in order to derive a multidimensional perceptual space for the stimuli. Three semantic components were derived using Principal Components Analysis (PCA) of property ratings for the same set of six effects. Multiple Regression Analysis (MRA) was used to relate the perceptual dimensions and semantic components, the results of which provide a control structure for a commercially available effects processor. The study revealed a direct mapping between three perceptual dimensions and three semantic component scales, those being labeled as “sharp-dull, ”“diffusecompact, ”and “thick-thin”(in Japanese, surudoi-nibui, hirogotta-kojinmarishita, and usui-atsui).

Perception of the Quality of Sound Amplitude-modulated with Triangular Waves

This paper discusses multidimensional perceptual space derived from the results of psychoacoustical experiments on similarities in the quality of sounds amplitude-modulated by nine triangular waves different in rise- and fall-times. For sinusoidal (1 kHz) and random-noise carriers, three experiments were conducted with different modulation frequencies, namely 8, 16 and 32 Hz. In each experiment, similarities in sound quality for stimuli with modulation depths of 0.4, 0.8 and 1.0, as well as the original carrier wave, were rated. The similarities were analyzed by a multidimensional scaling method (ALSCAL), and three-dimensional configurations were derived. A common configuration correlated with the modulation depth was seen irrespective of carrier wave and modulation frequency. There was a perceptual dimension related to shape of amplitude modulation for all conditions except for noise carrier with 32-Hz modulation. The difference in rise time caused larger differences in sound quality than similar differences in fall time up to a modulation frequency of 16 Hz, irrespective of the kind of carrier wave.

Applying the semantic transformation method to product form design

A semantic transformation method for product form design is proposed. In this model, an image database for the relationships between the product shapes and image words is built using the membership functions of a fuzzy set, and a multidimensional perceptual space for the relationships between the abstract image words and the embodiment shape regulating rules is also constructed using the multidimensional scaling (MDS) method. A computer program is constructed by integrating the technique of constructing B-splines, the image database and fuzzy query operations to provide a CAD environment in which 3D basic models of a product can be constructed by starting with inputting an image word(s) for describing the image of the required product. After a basic product model has been constructed, new product forms can further be generated by regulating the shape of the basic model using the suggested embodiment shape regulation rule which is obtained by inputting a required image to analyze the direction cosines of the embodiment shape regulation rules with respect to the required image in the multidimensional semantic recognition space. Though automotive form design is taken as an example in this study, this method can also be used to develop other products.

A consideration of timbre in broadband harmonic complex tones with different fundamental frequencies and spectral envelopes

Similarities in timbre among 36 broadband complex tone stimuli were measured by a rating-scale method to derive multidimensional perceptual space for the stimuli. Fundamental frequencies of the stimuli were 100, 200, or 400 Hz, spectral envelopes were 0, −3, −6, or −9 dB/oct, and the numbers of components were 20, 30, or 40. The obtained similarities were analyzed by the method of multidimensional scaling, and a three-dimensional configuration was drawn. Distances among stimuli in the configuration did not show good agreement with differences in the physical frequency spectrum. The distances in the perceptual space were then compared with differences in the ‘‘masked frequency spectrum’’ [Ozawa et al., Proc. 15th ICAIII , 465–468 (1995)] which was the frequency spectrum in terms of the loudness of the narrow-band frequency component of the stimuli partially masked by each other. The agreement between them was better than that in the case of the physical frequency spectrum. This suggests that the masked frequency spectrum of a sound is a good approximation to the final spectrum perceived in hearing.

Perceptual characterization of images degraded by blur and noise: experiments.

The notion of a perceptual space is useful for characterizing images in terms of their perceptual image quality. It is shown that images degraded by blur and noise can be assigned positions in a multidimensional perceptual space and that quality and its underlying attributes sharpness and noisiness can be associated with directions (or vectors) in this space. The perceptual space is constructed using multidimensional scaling (MDS) techniques. Two different MDS approaches are used, one making use of the perceived dissimilarity between the images and another making use of the scaled perceptual attributes sharpness and noisiness. The two alternative approaches lead to stimulus configurations that can be approximately related by a linear transformation, and the results from both MDS approaches can be combined to produce one perceptual space for each scene. A two-dimensional perceptual space adequately represents the processed images for all three scenes that are used, and the perceptual spaces obtained for all scenes are very similar. The directions of the attribute vectors in the perceptual space indicate that unsharpness and noisiness are approximately orthogonal attributes, which implies that there is little interaction between these attributes. The impairment vector, whose direction is opposite to that of the quality vectors, lies between the unsharpness and noisiness vectors at an angle of approximately 30 degrees between the unsharpness and impairment vectors.

Perceptual characterization of images degraded by blur and noise: model.

Reliable and economic methods for assessing image quality are essential for designing better imaging systems. Although reliable psychophysical methods are available for assessing perceptual image quality with the help of human subjects, the cost of performing such experiments prevents their use for evaluating large amounts of image material. This has led to an increasing demand for objective methods for estimating image quality. The perceived quality of an image is usually determined by several underlying perceptual attributes such as sharpness and noisiness. In the accompanying paper [J. Opt. Soc. Am. A 13, 1166-1177 (1996)] it is demonstrated that the relationships between images on the one hand and judgments on attributes and overall quality by subjects on the other hand can be characterized in a multidimensional perceptual space. In this perceptual space the images are represented by points, and the strengths of their perceptual attributes are modeled by the projections of these image positions onto the attribute axes. In analogy with the perceptual space we will introduce a psychometric space in which the positions of the images are determined by objective measures on the images. In the case of images degraded by blur and noise the stimulus coordinates are functions of the estimated spread of the blurring kernel and the estimated standard deviation of the noise, respectively. According to the model presented in this paper, the perceptual attributes of images can be estimated in three steps. In the first step the physical parameters (blur spread and noise standard deviation) are estimated from the images. In the second step these estimates are used to position the images in psychometric space. In the third step the attribute strengths are derived by projecting the alter image positions onto the attribute axes. We show that the attributes and the quality thus estimated correlate well with the perceived attributes and quality.

Sensitivity to the distinctive features of vowels in newborn speech segmentation

A previous study investigating the unit of speech perception in newborns [K. L. Kaye, J. Acoust. Soc. Am. 92, 2299(A) (1992)] yielded results suggesting that speech processing in newborns requires both the definition of the multidimensional perceptual space of the utterances in terms of small perceptual units, and the chunking of phenoemes into syllables for cognitive processing in memory. The present study focused on the perceptual process, investigating whether newborns are sensitive to the distinctive features of vowels. A vowel can be characterized by three opposed distinctive features. Using an operant (‖S‖) sucking procedure, one group of newborns received, over earphones, a presentation set with 0 distinctive feature variation, a second group with greater than 0 but less than 1 distinctive feature variation, and a third group with 2 distinctive features variation between the computer synthesized vowels in the set. Results indicated that responding is affected by the number of distinctive features required to define the vowel set, and together these studies indicate that newborns can segment speech in terms of syllables, phonemes, and distinctive features. Distinctive features are normally defined in articulatory terms, yet newborns do not have the appropriate articulatory equipment. The theoretical implications of this will be discussed.

An exploration of phoneme structure and models of classification for place of articulation

Speech perception research has typically investigated phoneme categories and specified trading relation effects in terms of limits defined along single dimensions. However, phoneme categories vary along a number of significant physical dimensions, with stimuli distributed across the multidimensional perceptual space often differing in goodness of category membership. The current study used a set of synthetic CV syllables based on F2- and F3-onset frequencies to examine the internal structure of several phonetic categories within the same vowel context. Experiment 1 used a free classification task to establish the perceptual structure of categories differing in place of articulation. Experiments 2, 3, and 4, respectively, related response times of a speeded classification task with category goodness ratings and a multidimensional phonetic perceptual space based upon similarity ratings. The multidimensional space was quite distinct compared to a prior space obtained for a different vowel context. Results are discussed in terms of prototype and exemplar models of phonetic classification. [Research supported in part by grants from NSF and AFOSR to R. E. Pastore, and NIH.] a)Now at Indiana University.

Sex, handedness and side of nose modulate human odor perception

Multidimensional scaling was used to analyze odor similarity judgments obtained by monorhinic (single nostril) stimulation from normal subjects ( N=52), equally by sex and handedness. Neither sex nor handedness nor side of nose appeared to alter the position of stimuli on a two-dimensional map of odor similarity. However, women produced significantly more consistent maps than men. This result was not due to differential utilization of axes in the multidimensional perceptual space, nor to differences in verbal labeling. Left versus right nostril asymmetries were significantly greater in dextrals.

The timbre of sung vowels

The perception of timbre differences in a vowel sung by eight male and seven female singers has been investigated by means of two types of listening experiments: (1) using the paradigm of the comparison of similarity, and (2) using judgments on 21 semantic bipolar scales. Using INDSCAL analysis for the similarity-comparison data and MDPREF analysis for the semantic-scale judgments, vowel configurations in a multidimensional perceptual space were derived, as well as a space that showed the weighting of perceptual dimensions by individual listeners (INDSCAL). The interpretation of semantic scales was represented by directions in the perceptual space (MDPREF). The perceptual vowel configurations, either based on timbre similarities or semantic scales judgments, were comparable. Broadly, semantic scales clustered into the categories vocal technique, general evaluation, vibrato, clarity, and sharpness. These five clusters were not independent and could be described in two dimensions. Timbre differences could be predicted on the basis of differences in 1/3-oct spectra of the vowels. It showed up that only sharpness had a constant interpretation for the various stimulus sets and was roughly related to the slope of the spectrum. One experiment, using a song phrase, extended the results to a more general domain.

Decision rules in the perception and categorization of multidimensional stimuli.

This article examines decision processes in the perception and categorization of stimuli constructed from one or more components. First, a general perceptual theory is used to formally characterize large classes of existing decision models according to the type of decision boundary they predict in a multidimensional perceptual space. A new experimental paradigm is developed that makes it possible to accurately estimate a subject's decision boundary in a categorization task. Three experiments using this paradigm are reported. Three conclusions stand out: (a) Subjects adopted deterministic decision rules, that is, for a given location in the perceptual space, most subjects always gave the same response; (b) subjects used decision rules that were nearly optimal; and (c) the only constraint on the type of decision bound that subjects used was the amount of cognitive capacity it required to implement. Subjects were not constrained to make independent decisions on each component or to attend to the distance to each prototype.

Matching of “physical” and “perceptual” spaces for vowels

An algorithm for matching physical and perceptual spaces for psychological stimuli will be described. Target points for each stimulus class must be chosen in a multidimensional perceptual space. The physical space consists of a multidimensional measurement space, in which measurements are made of each stimulus for a large number of subjects. A linear transformation from the measurement space to the perceptual space is determined such that the mean square distance between target points and transformed measurement points is minimized. There is no requirement that the dimensionality of the measurement and perceptual spaces be the same. Thus the algorithm can be used to redefine the measurement space with fewer dimensions such that the correspondence with predefined stimulus categories is maximized. This procedure has been tested using vowels spoken in an /hVd/ context, six principal components for measurement parameters, and a three‐dimensional perceptual space. Target positions in the perceptual space were based on published data from multidimensional scaling experiments for vowels. The resultant transformation has been used to map vowels to colors for use in a speech training aid for the hearing impaired. Experimental results will be given. [Work supported by the The Whitaker Foundation.]

A Dynamic Spatial Analysis of Changes in Aesthetic Responses

Models of evaluative judgment in applied aesthetics generally assume that movements of objects' positions in a multidimensional perceptual space will produce corresponding changes in preferences. However, such spatial representations have usually been tested using static designs or, at best, longitudinal studies that fail to tie perceptual movements to shifts in affective response. This study reports what we believe to be a first dynamic analysis of changes in aesthetic responses. Specifically, twenty-nine aesthetically naive subjects supplied perceptual and affective ratings of twenty art prints on four occasions spaced a week apart. Multiple discriminant analysis (MDA) of the perception data created an MDA space representing each person's perceptions of each print at the beginning and end of the period. We then constructed each individual's preference function based on the MDA space, used beginning and ending perceived positions to compute changes in that preference function, regarded these as predictions of changes in actual affect, and correlated predicted with actual affective shifts to obtain a validity assessment of about r2 = .25 for our dynamic spatial analysis of trends in tastes.

Perception of simulated propeller cavitation.

A stochastic model is proposed to describe the perceptual processes that underlie the classification of complex multidimensional sounds, such as passive sonar signatures. The model is based on four assumptions: (1) complex sounds may be represented psychologically as points in a multidimensional perceptual space, (2) categories are represented theoretically as distributions in this space centered at ideal category members or prototype, (3) the category distributions determine the conditional stimulus probabilities and have multivariate Gaussian form, and (4) individual dimensions in the perceptual space may be weighted differentially to reflect a listener's attentional processes. To evaluate the model, two groups were tested in an eight-category classification task involving 16 simulated propeller cavitation sounds. A perceptual structure was determined for the sounds in a preliminary non-metric multidimensional scaling study. The two groups received category assignments that stressed different properties of the cavitation sounds. An observed confusion matrix was derived by fitting the model to the observed data. Overall, comparison of the obtained and theoretical data indicated that the model provides a reasonable description of how listeners classify complex simulated sonar sounds. The assumption that listeners can selectively and independently adjust the relative importance of the perceptual dimensions was also supported. The utility of the proposed model as a tool for the development of preprocessing aids and training programs for sonar operators is discussed.

Perceptual Veridicality in Esthetic Communication: A Model, General Procedure, and Illustration

The validity of much artistic criticism rests upon two crucial assumptions about the nature of esthetic communication. The first (Hypothesis H1) holds that objective esthetic features are accurately perceived by audience members. The second (Hypothesis H2) asserts that such perceptual veridicality does not depend upon one's degree of education or training, so that critics and audience members tend to share cognitive responses t o artistic messages and offerings. However, the empirical verification of H1 and H2 has received little attention. Indeed suitable models and methods for addressing these issues cppear to be missing. Accordingly. this article proposes a model of perceptual veridicality in esthetic communication. describes a procedure for assessing perceptual accuracy. and illustrates this approach in a study of perceptual responses to stylistic aspects of classical piano performances. Specifically. a keyboard piece by Bach is played in all 16 possible combinations of variations in 4 stylistic features: tempo, rhythm, dynamics, and phrasing. Subjects' adjectival ratings of these performances are factor analyzed into a reduced set of perceptual indices that are then submitted to multiple discriminant analysis to obtain a multidimensional perceptual space. The correlational fits of this perceptual space to the objective stylistic features support the hypotheses by indicating high overall perceptual veridicality (H1) and equivalent accuracy for expert and naive subjects (H2).