Acoustic Basis Research Articles

Effects of spectral manipulations of music mixes on musical scene analysis abilities of hearing-impaired listeners.

Music pre-processing methods are currently becoming a recognized area of research with the goal of making music more accessible to listeners with a hearing impairment. Our previous study showed that hearing-impaired listeners preferred spectrally manipulated multi-track mixes. Nevertheless, the acoustical basis of mixing for hearing-impaired listeners remains poorly understood. Here, we assess listeners' ability to detect a musical target within mixes with varying degrees of spectral manipulations using the so-called EQ-transform. This transform exaggerates or downplays the spectral distinctiveness of a track with respect to an ensemble average spectrum taken over a number of instruments. In an experiment, 30 young normal-hearing (yNH) and 24 older hearing-impaired (oHI) participants with predominantly moderate to severe hearing loss were tested. The target that was to be detected in the mixes was from the instrument categories Lead vocals, Bass guitar, Drums, Guitar, and Piano. Our results show that both hearing loss and target category affected performance, but there were no main effects of EQ-transform. yNH performed consistently better than oHI in all target categories, irrespective of the spectral manipulations. Both groups demonstrated the best performance in detecting Lead vocals, with yNH performing flawlessly at 100% median accuracy and oHI at 92.5% (IQR = 86.3-96.3%). Contrarily, performance in detecting Bass was arguably the worst among yNH (Mdn = 67.5% IQR = 60-75%) and oHI (Mdn = 60%, IQR = 50-66.3%), with the latter even performing close to chance-levels of 50% accuracy. Predictions from a generalized linear mixed-effects model indicated that for every decibel increase in hearing loss level, the odds of correctly detecting the target decreased by 3%. Therefore, baseline performance progressively declined to chance-level at moderately severe degrees of hearing loss thresholds, independent of target category. The frequency domain sparsity of mixes and larger differences in target and mix roll-off points were positively correlated with performance especially for oHI participants (r = .3, p < .01). Performance of yNH on the other hand remained robust to changes in mix sparsity. Our findings underscore the multifaceted nature of selective listening in musical scenes and the instrument-specific consequences of spectral adjustments of the audio.

Acoustic phonetics: Notes on the evolution of /ti̯, ki̯/ yod contexts in Spanish

The explanation for the evolution of /ti̯/ and /ki̯/ yod contexts has been based on articulatory reasons. However, sound change has an important auditory and acoustic basis. This paper deals with two main topics: (a) it examines the confluence of the phonetic realisations of dental and velar stops in /ti̯/ and /ki̯/, and (b) it seeks to determine whether voicing occurs after the assibilation process. The results show that the allophones for /t/ and /k/ display acoustic similarities regarding point of articulation cues, which could explain misperceptions. Voicing also seems to be very frequent in these phonetic realisations, which points to a process simultaneous with assibilation.

Affective prosody in grunts of young chimpanzees

Humans acoustically encode affective information into their utterances. This ability, known as ‘affective prosody’, takes pre-linguistic roots and plays an important role in human communication throughout the lifespan by enabling listeners to disambiguate the meaning of speakers’ utterances. Adopting a comparative-developmental perspective, we ask whether such an ability may also be present in the vocalisations of young chimpanzees. We examine the acoustic characteristics of grunt vocalisations known to be related to affective expression in other non-human species and show that grunts produced during positive, neutral, and negative contexts can indeed be distinguished on this acoustic basis. Further, our data provide new and unexpected insights into ontogenetic constraints in chimpanzee vocal production, finding that almost all acoustic parameters in early chimpanzee grunts are strongly correlated. We conclude that affective prosody is likely a characteristic of young chimpanzee vocal behaviour and speculate that affect may be more flexibly expressed through call acoustics with increasing age as chimpanzees gain greater control over their vocal apparatus.

Heritability of Sound Processing Deficits in Autism: Neural Insights

Heritability of Sound Processing Deficits in Autism: Neural Insights

Comparison and Analysis of Timbre Fusion for Chinese and Western Musical Instruments.

Timbre fusion is the theoretical basis of instrument acoustics and Chinese and Western orchestral acoustics. Currently, studies on timbre fusion are mainly focused on Western instruments, but there are some studies on the timbre fusion of Chinese instruments. In this paper, the characteristics of timbre fusion for Chinese and Western instruments are explored, focusing on the subjective attributes and objective acoustic parameters, and a series of experiments is carried out. First, a database containing 518 mixed timbre stimuli of Chinese and Western instruments was constructed to provide basic data that are necessary for the subjective and objective analyses of timbre fusion. We designed and conducted a subjective evaluation experiment of timbre perception attributes based on the method of successive categories. The experimental data were processed using statistical approaches, such as variance analysis, multidimensional preference analysis, and correlation analysis, and we studied the influence of the temporal envelopes and instrument types on fusion, segregation, roughness, and pleasantness. In addition, the differences between Chinese and Western instruments were compared based on these four perception attributes. The results show that fusion and segregation are the most important attributes for Chinese instrument timbre, while roughness is the most important attribute for Western instrument timbre. In addition, multiple linear regression, random forest, and multilayer perceptron were used to construct a set of timbre fusion models for Chinese and Western instruments. The results show that these models can better predict the timbre fusion attributes. It was also found that there are some differences between the timbre fusion models for Chinese and Western instruments, which is consistent with the analysis results of subjective experimental data. The contribution of acoustic objective parameters to the fusion model is also discussed.

Set the tone: Trustworthy and dominant novel voices classification using explicit judgement and machine learning techniques.

Prior research has established that valence-trustworthiness and power-dominance are the two main dimensions of voice evaluation at zero-acquaintance. These impressions shape many of our interactions and high-impact decisions, so it is crucial for many domains to understand this dynamic. Yet, the relationship between acoustical properties of novel voices and personality/attitudinal traits attributions remains poorly understood. The fundamental problem of understanding vocal impressions and relative decision-making is linked to the complex nature of the acoustical properties in voices. In order to disentangle this relationship, this study extends the line of research on the acoustical bases of vocal impressions in two ways. First, by attempting to replicate previous finding on the bi-dimensional nature of first impressions: using personality judgements and establishing a correspondence between acoustics and voice-first-impression (VFI) dimensions relative to sex (Study 1). Second (Study 2), by exploring the non-linear relationships between acoustical parameters and VFI by the means of machine learning models. In accordance with literature, a bi-dimensional projection comprising valence-trustworthiness and power-dominance evaluations is found to explain 80% of the VFI. In study 1, brighter (high center of gravity), smoother (low shimmers), and louder (high minimum intensity) voices reflected trustworthiness, while vocal roughness (harmonic to noise-ratio), energy in the high frequencies (Energy3250), pitch (Quantile 1, Quantile 5) and lower range of pitch values reflected dominance. In study 2, above chance classification of vocal profiles was achieved by both Support Vector Machine (77.78%) and Random-Forest (Out-Of-Bag = 36.14) classifiers, generally confirming that machine learning algorithms could predict first impressions from voices. Hence results support a bi-dimensional structure to VFI, emphasize the usefulness of machine learning techniques in understanding vocal impressions, and shed light on the influence of sex on VFI formation.

Perception of gender in children's voices

Research shows that gender in the voices of prepubescent children can be identified relatively well, despite the absence of reliable anatomical differences related to their vocal tract morphology. This implies that information about differences in girls’ and boys’ voices also resides in behavioral and cultural aspects of speech and not exclusively in the acoustic cues corresponding to anatomical differences. The observed improved gender identification (gID) for sentences over syllables suggests that longer stretches of speech provide listeners with a richer acoustic basis for their decisions. Here, we introduce two additional factors that may affect gID: speaking style and children’s dialect. Children (n = 92) ages 8;0–12;4 years, boys (n = 45) and girls (n = 47) from Ohio, Wisconsin, and North Carolina produced isolated syllables, read sentences, and spontaneous utterances. Listeners were young adults from Ohio. Expectedly, gID accuracy for sentences/utterances was greater (66%) than for syllables (55%), and for older than younger children. Dialect was a significant predictor for younger (but not older) children, with the highest gID for Ohio. Overall, spontaneous utterances did not provide more gender information than read sentences except for older children from North Carolina, suggesting that cultural traits in conversational dynamics can also be useful to listeners in gID.

The acoustic bases of human voice identity processing in dogs

Speech carries identity-diagnostic acoustic cues that help individuals recognize each other during vocal–social interactions. In humans, fundamental frequency, formant dispersion and harmonics-to-noise ratio serve as characteristics along which speakers can be reliably separated. The ability to infer a speaker’s identity is also adaptive for members of other species (like companion animals) for whom humans (as owners) are relevant. The acoustic bases of speaker recognition in non-humans are unknown. Here, we tested whether dogs can recognize their owner’s voice and whether they rely on the same acoustic parameters for such recognition as humans use to discriminate speakers. Stimuli were pre-recorded sentences spoken by the owner and control persons, played through loudspeakers placed behind two non-transparent screens (with each screen hiding a person). We investigated the association between acoustic distance of speakers (examined along several dimensions relevant in intraspecific voice identification) and dogs’ behavior. Dogs chose their owner’s voice more often than that of control persons’, suggesting that they can identify it. Choosing success and time spent looking in the direction of the owner’s voice were positively associated, showing that looking time is an index of the ease of choice. Acoustic distance of speakers in mean fundamental frequency and jitter were positively associated with looking time, indicating that the shorter the acoustic distance between speakers with regard to these parameters, the harder the decision. So, dogs use these cues to discriminate their owner’s voice from unfamiliar voices. These findings reveal that dogs use some but probably not all acoustic parameters that humans use to identify speakers. Although dogs can detect fine changes in speech, their perceptual system may not be fully attuned to identity-diagnostic cues in the human voice.

Evaluation of Ashrae background noise criteria through in situ measurement

Chapter 49 of the ASHRAE Applications Handbook establishes background noise design criteria for typical interior occupancies. These criteria are referenced and commonly used as an acoustical basis of design for codes, such as the International Green Construction Code, and for rating systems, such as LEED, as well as other project documents and design standards. They are set forth to determine the level of occupant comfort from mechanical systems. The authors have observed that compliance with these standards is not always necessary to avoid complaints. In fact, the benefit of compliance with the standards is limited to the protection of the acoustician, rather than meeting needs for the users of the space. This observation has motivated the authors to assess the established ASHRAE criteria as compared to measured interior sound levels with HVAC systems in operation. The authors will present objective data associated with noise measurements in specific HVAC applications. Using data from subjective determinations, the authors will propose a system for determination of occupant reaction that can be considered.

Exploring the Acoustic Perceptual Relationship of Speech in Parkinson's Disease.

Purpose Auditory perceptual judgments are commonly used to diagnose dysarthria and assess treatment progress. The purpose of the study was to examine the acoustic underpinnings of perceptual speech abnormalities in individuals with Parkinson's disease (PD). Method Auditory perceptual judgments were obtained from sentences produced by 13 speakers with PD and five healthy older adults. Twenty young listeners rated overall ease of understanding, articulatory precision, voice quality, and prosodic adequacy on a visual analog scale. Acoustic measures associated with the speech subsystems of articulation, phonation, and prosody were obtained, including second formant transitions, articulation rate, cepstral and spectral measures of voice, and pitch variations. Regression analyses were performed to assess the relationships between perceptual judgments and acoustic variables. Results Perceptual impressions of Parkinsonian speech were related to combinations of several acoustic variables. Approximately 36%-49% of the variance in the perceptual ratings were explained by the acoustic measures indicating a modest acoustic perceptual relationship. Conclusions The relationships between perceptual ratings and acoustic signals in Parkinsonian speech are multifactorial and involve a variety of acoustic features simultaneously. The modest acoustic perceptual relationships, however, suggest that future work is needed to further examine the acoustic bases of perceptual judgments in dysarthria.

On the Role of Generation Rules in Moderating the Beneficial Effects of Errorful Generation

Abstract. In participants’ learning of semantically related paired associates, such as whale-mammal, prior research has demonstrated that having participants first attempt to predict what the to-be-learned response to a given cue will be enhances subsequent cued recall of that response, even when such predictions are always wrong (e.g., Kornell et al., 2009 ). In six experiments, we evaluate the importance of such error-prone predictions having a semantic basis – versus an acoustic (rhyming) basis. Our results show that both semantic generation as well as semantically related materials seem necessary if errorful generation is to have positive effects; generation based on other rules and materials does not aid learning. Learners are not, however, metacognitively aware of such benefits of generating errors.

Acoustic cues to individuality in wild male adult African savannah elephants (Loxodonta africana).

The ability to recognize conspecifics plays a pivotal role in animal communication systems. It is especially important for establishing and maintaining associations among individuals of social, long-lived species, such as elephants. While research on female elephant sociality and communication is prevalent, until recently male elephants have been considered far less social than females. This resulted in a dearth of information about their communication and recognition abilities. With new knowledge about the intricacies of the male elephant social structure come questions regarding the communication basis that allows for social bonds to be established and maintained. By analyzing the acoustic parameters of social rumbles recorded over 1.5 years from wild, mature, male African savanna elephants (Loxodonta africana) we expand current knowledge about the information encoded within these vocalizations and their potential to facilitate individual recognition. We showed that social rumbles are individually distinct and stable over time and therefore provide an acoustic basis for individual recognition. Furthermore, our results revealed that different frequency parameters contribute to individual differences of these vocalizations.

ЖЕСТОВЫЕ ЯЗЫКИ КАК ПОЛНОЦЕННОЕ СРЕДСТВО КОММУНИКАЦИИ

The article considers sign languages as a full-fledged communicative language system used by deaf people in communication with each other. Unlike sounding languages, whose expression plan is based on an acoustic basis, sign languages are based on a kinetic (gestural-mimic) principle. Like sounding languages, sign languages are self-sufficient communication systems.

Individuality in houbara chick calls and its dynamics throughout ontogeny

In many taxa, breeding success depends heavily on reliable vocal recognition between parents and offspring. Although the acoustic basis of this recognition has been explored in several species, few studies have examined the evolution of acoustic cues to identity across development. Here, in a captive breeding program, we investigated for the first time the acoustic signals produced by North African houbara bustard Chlamydotis undulata undulata chicks. Two call types (contact and distress) were recorded from 15 chicks in 4 age classes. Acoustic analyses showed that the acoustic parameters of the calls varied systematically with age in both contact and distress calls. However, both call types remained highly stereotyped and individualized between chicks at every tested age, indicating that calls encode reliable information about individual identity throughout development, thus potentially enabling the mother to distinguish her own chicks through their development up to fledging. Playback experiments are now needed to verify such parent-chick recognition in houbara bustards and its efficiency across chick ontogeny.

Parasitic begging calls of nestmate-evictor common cuckoos stimulate more parental provisions by red-winged blackbirds than calls of nest-sharing brown-headed cowbirds

Parasites often manipulate host behaviors to achieve their own selfish fitness goals. However, the efficiency with which parasitic begging calls solicit foster parental care has not yet been compared across different avian obligate host-brood parasite systems. For example, the begging calls of nestmate-evictor parasites are predicted to solicit sufficient levels of foster parental provisioning for the sole parasitic chick in the nest, whereas the calls of nest-sharing parasites combine together with the begging by host nestmates to solicit provisions for the whole brood. We studied the red-winged blackbird (Agelaius phoeniceus), a host of the brood parasitic brown-headed cowbird (Molothrus ater), to test the effects of begging call playbacks of nestmate-evictor common cuckoos (Cuculus canorus) or nestmate-sharing cowbirds upon parental feeding patterns. As predicted, cuckoo calls elicited more parental feeding trips and the amount of food delivered than cowbird calls. Food provisioning to nestlings while hearing cuckoo begging calls was similar to that while hearing redwing calls, and both were higher relative to a control silence treatment, which suggested that the begging call acoustics of the cuckoo served as an efficient stimulus for parental care in this cuckoo-naive host. The study also confirms that cowbird calls are not supernormal stimuli for parental provisions in this host species, as redwing begging calls themselves were similarly effective stimulants for conspecific parental provisioning behaviors. Future research should examine the acoustical bases and perceptual biases present in the cuckoo’s begging calls to efficiently solicit parental provisioning in both naive and coevolved hosts. Nestlings of different avian brood parasites use distinct strategies to survive and solicit parental provisions by heterospecific foster parents: some of them evict or otherwise kill host nestmate to grow up alone in the nest (e.g., common cuckoos), whereas others typically share the nest with host chicks (e.g., brown-headed cowbirds). However, the efficiency to solicit parental care through begging calls by brood parasitic young with respect to their nestmate-evictor versus nest-sharing strategies has not yet been evaluated. We focused on a cuckoo-naive and cowbird-exposed host species, the red-winged blackbird, to compare the effects of begging call playbacks of parasites and conspecifics, relative to silence controls. We found that the begging calls of cuckoos, rather than the cowbirds, elicited more parental feeding in this cuckoo-naive host. This implied that it was the nestmate-evictor strategy, rather than host familiarity, that improved the efficiency of the parasitic begging calls. Our results provide the first experimental data on the efficiency of begging calls between cuckoos and cowbirds within the same host species, and it contributes to our understanding of the divergent ontogenetic strategies of evolutionarily distinct avian brood parasites.

Unraveling the species diversity and relationships in the Leptodactylus mystaceuscomplex (Anura: Leptodactylidae), with the description of three new Brazilian species.

Members of the Leptodactylus mystaceus species complex are widely distributed in forests and open formations of South America east of the Andes. Species of the complex are morphologically similar or indistinguishable among each other, but acoustic data have been the cornerstone for species discrimination across their geographic ranges. In this paper, we re-examine the monophyly, species diversity, and relationships in the L. mystaceus complex on the basis of morphology, coloration, acoustics, and DNA sequences. Morphological and color patterns originally used to the allocation of species to the L. mystaceus complex are also reassessed. Our results revealed three new species from the Brazilian Atlantic Forest and Cerrado, which are named and described herein, based mainly on acoustic and molecular data. Populations assigned to the lineage widely distributed across the South American Dry Diagonal (DD), reported in this study as L. cf. mystaceus, is likely paraphyletic with respect to the nominal species (Amazonian lineage), but additional data are still needed to address the taxonomic status of the DD lineage.

A formant study of the alveolar versus retroflex contrast in three Central Australian languages: Stop, nasal, and lateral manners of articulation.

This study presents formant transition data from 21 speakers for the apical alveolar∼retroflex contrast in three neighbouring Central Australian languages: Arrernte, Pitjantjatjara, and Warlpiri. The contrast is examined for three manners of articulation: stop, nasal, and lateral /t ∼ ʈ/ /n ∼ ɳ/, and /l ∼ ɭ/, and three vowel contexts /a i u/. As expected, results show that a lower F3 and F4 in the preceding vowel signal a retroflex consonant; and that the alveolar∼retroflex contrast is most clearly realized in the context of an /a/ vowel, and least clearly realized in the context of an /i/ vowel. Results also show that the contrast is most clearly realized for the stop manner of articulation. These results provide an acoustic basis for the greater typological rarity of retroflex nasals and laterals as compared to stops. It is suggested that possible nasalization of the preceding vowel accounts for the poorer nasal consonant results, and that articulatory constraints on lateral consonant production account for the poorer lateral consonant results. Importantly, differences are noticed between speakers, and it is suggested that literacy plays a major role in maintenance of this marginal phonemic contrast.

Rytų aukštaičių uteniškių ilgųjų balsių priegaidės: istorinė analizė ir eksperimentinis tyrimas

Pitch accents of monophthongs in High Lithuanian (Utena subdialect): historical survey and experimental investigation The present paper deals with the question of whether there is an acoustic basis for pitch accent distinction in High Lithuanian (i.e. in Utena subdialect). First, a historical survey was conducted in which theoretical frameworks of Kursaitis, Baranauskas, Jaunius were discussed. In addition, the data from experimental studies were taken into account. The second part of this article deals with a new experimental investigation in which both tone sustainability coefficient and intensity extrema of long stressed vowels were estimated. In comparison to other dialects, none of these parameters appeared to be of great significance. On the basis of these results a conclusion that there is no reliable theoretical or experimental basis for the pitch accent functionality in Utena subdialect might be drawn. The cause of such prosodic process might be explained by a significant reduction in vowel quantity.

Modeling the perception of children's age from speech acoustics

Adult listeners were presented with /hVd/ syllables spoken by boys and girls ranging from 5 to 18 years of age. Half of the listeners were informed of the sex of the speaker; the other half were not. Results indicate that veridical age in children can be predicted accurately based on the acoustic characteristics of the talker's voice and that listener behavior is highly predictable on the basis of speech acoustics. Furthermore, listeners appear to incorporate assumptions about talker sex into their estimates of talker age, even when information about the talker's sex is not explicitly provided for them.

Study on the order target of the sporty sound quality of the vehicle exhaust noise under acceleration

Correlational studies of order noise sample tuning and subjective evaluation test of sound quality were conducted to achieve sporty sound quality and confirm the correlation between the auditory sense (subjective) and the order noise level (objective) of vehicle exhaust noise under acceleration. First, the frequency range and the order ingredient of sporty quality noise were confirmed by a study of ear-hearing subjective feeling on the basis of physiological acoustics. By using an order tuning software that was developed independently, the second, fourth, and sixth order noise A-weighting sound pressure level (dB(A)) of the exhaust noise of an objective vehicle were tuned segmentally into numerous sound samples. Furthermore, samples with high sporty sound quality were selected through subjective evaluation, and the A-weighting sound pressure level (dB(A)) distributions of the second, fourth, and sixth order noise of these samples were analyzed. Consequently, the relative size relations of the second, fourth, and sixth order noise of all the exhaust noise with sporty sound quality were determined. In addition, the curve distribution zones of the corresponding order noise were formed and the order quantitative target of the sporty sound quality was considered. Finally, four passenger vehicles with representative sound qualities (sporty, quiet, and characterless) on the market were selected as the benchmark vehicles; their order noise was objectively tested and their sound qualities subjectively evaluated. Meanwhile, the order noise objective test result was compared with the order target. Results showed that when the fourth and sixth order noise curves relative to the second order noise curves were within the order target zones at most of the engine speeds, the exhaust noise of the vehicle had considerable sporty sound quality; otherwise, it did not have such a sound. Therefore, the order target of the sporty sound quality was accurate and effective.