Vocal System Research Articles

Analysis of aperiodicity in artistic Noh singing voice using an impulse sequence representation of excitation source.

Aperiodicity in the voice source is caused by changes in the vocal fold vibrations, other than the normal quasi-periodicity and the turbulence at the glottis. The aperiodicity appears to be one of the main properties that is responsible for conveying the emotion in artistic voices. In this paper, the feasibility of representing the excitation source characteristics in artistic (Noh) singing voice by an impulse-like sequence in the time domain is examined. The impulses at the glottal closure instants contribute to the major excitation of the vocal tract system. The sequence of such impulses produces harmonics of the fundamental frequency in the spectrum. The amplitude variation or amplitude modulation (AM) of these impulses in the sequence contributes to the aperiodicity in the excitation, and can result in appearance of subharmonics in the spectrum. The variation in the impulse intervals or frequency modulation (FM) can also contribute to the aperiodicity in the excitation. The aperiodic component of the excitation in the Noh voice is examined in the impulse-like sequence derived from the signal using the single frequency filtering analysis. The effects of aperiodicity are explained for synthetic AM and FM sequences of impulses using spectrograms and saliency plots.

The "Law of Brevity" in animal communication: Sex-specific signaling optimization is determined by call amplitude rather than duration.

The efficiency of informational transfer is one of the key aspects of any communication system. The informational coding economy of human languages is often demonstrated by their almost universal fit to Zipf's “Law of Brevity,” expressing negative relationship between word length and its usage frequency. Animal vocal systems, however, provided mixed results in their adherence to this relationship, potentially due to conflicting evolutionary pressures related to differences in signaling range and communicational needs. To examine this potential parallel between human and animal vocal communication, and also to explore how divergent, sex‐specific, communicational settings affect signaling efficiency within a species, we examined the complete vocal repertoire of rock hyraxes (Procavia capensis). As male and female hyraxes differ in their sociality levels and male hyraxes vocal repertoire is dominated by sexual advertisement songs, we hypothesized that sex‐specific vocal repertoires could be subjected to different signaling optimization pressures. Our results show that the sexes differ in repertoire size, call usage, and adherence to coding efficiency principles. Interestingly, the classic call length/call usage relationship is not consistently found in rock hyraxes. Rather, a negative relationship between call amplitude and call usage is found, suggesting that the efficiency of the vocal repertoire is driven by call amplitude rather than duration. We hypothesize that, in contrast to human speech that is mainly intended for short distance, the need for frequent long‐range signaling shapes an animal's vocal repertoire efficiency according to the cost of call amplitude rather than call length. However, call duration may be a secondary factor affecting signaling efficiency, in cases where amplitude is under specific selection pressures, such as sexual selection.

Detection of glottal closure instant and glottal open region from speech signals using spectral flatness measure

This paper proposes an approach using spectral flatness measure to detect the glottal closure instant (GCI) and the glottal open region (GOR) within each glottal cycle in voiced speech. The spectral flatness measure is derived from the instantaneous spectra obtained in the analysis of speech using single frequency filtering (SFF) and zero time windowing (ZTW) methods. The Hilbert envelope of the numerator of group delay (HNGD) spectrum at each instant of time is obtained using the ZTW method. The HNGD spectrum highlights the important (like resonances) spectral characteristics of the vocal tract system at each instant of time. The dynamic characteristics of the vocal tract system can be tracked by the spectral flatness feature of the HNGD spectrum, thus bringing out the characteristics of the vocal tract system when the subglottal region is coupled with the supraglottal region during the open phase of the glottal cycle. The SFF spectra at each instant change significantly at the location of the GCI. The GCIs can be detected using the changes in the spectral flatness information derived from the SFF spectra. The proposed methods of detection of GCI and GOR is compared with several existing methods.

Sound sequences in birdsong: how much do birds really care?

The complex and melodic nature of many birds' songs has raised interest in potential parallels between avian vocal sequences and human speech. The similarities between birdsong and speech in production and learning are well established, but surprisingly little is known about how birds perceive song sequences. One popular laboratory songbird, the zebra finch (Taeniopygia guttata), has recently attracted attention as an avian model for human speech, in part because the male learns to produce the individual elements in its song motif in a fixed sequence. But psychoacoustic evidence shows that adult zebra finches are relatively insensitive to the sequential features of song syllables. Instead, zebra finches and other birds seem to be exquisitely sensitive to the acoustic details of individual syllables to a degree that is beyond human hearing capacity. Based on these findings, we present a finite-state model of zebra finch perception of song syllable sequences and discuss the rich informational capacity of their vocal system. Furthermore, we highlight the abilities of budgerigars (Melopsittacus undulatus), a parrot species, to hear sequential features better than zebra finches and suggest that neurophysiological investigations comparing these species could prove fruitful for uncovering neural mechanisms for auditory sequence perception in human speech. This article is part of the theme issue 'What can animal communication teach us about human language?'

Effects of imidacloprid, a neonicotinoid insecticide, on the echolocation system of insectivorous bats

Imidacloprid, a widely used neonicotinoid insecticide, has led to a decline in the honey bee population worldwide. An invertebrate insect prey with neonicotinoid toxicity can adversely affect insectivores, such as echolocating bats. The aim of the current study was to examined whether imidacloprid toxicity may interfere echolocation system such as vocal, auditory, orientation, and spatial memory systems in the insectivorous bat. By comparing the ultrasound spectrum, auditory brainstem-evoked potential, and flight trajectory, we found that imidacloprid toxicity may interfere functions in vocal, auditory, orientation, and spatial memory system of insectivorous bats (Hipposideros armiger terasensis). As suggested from immunohistochemistry and western blots evidences, we found that insectivorous bats after suffering imidacloprid toxicity may decrease vocal-related FOXP2 expressions in the superior colliculus, auditory-related prestin expressions in the cochlea, and the auditory-related otoferlin expressions in the cochlea and the inferior colliculus, and cause inflammation and mitochondrial dysfunction-related apoptosis in the hippocampal CA1 and medial entorhinal cortex. These results may provide a reasonable explanation about imidacloprid-induced interference of echolocation system in insectivorous bats.

Does response modality influence conflict? Modelling vocal and manual response Stroop interference.

In the Stroop task, color words are presented in colored fonts and the task of the subject is to either name the word or name the color. If the word and font color are in agreement, then the stimulus is said to be congruent (e.g., RED in red font color); however, if the word and font color are not in agreement, the stimulus is said to be incongruent (e.g., RED in blue font color). Conflict in the Stroop task is measured by both RT and accuracy. In prior research, the amount of conflict differs depending on the response modality, vocal versus manual. We applied a model for multichoice decision-making (and confidence), the RTCON2 model (Ratcliff & Starns, 2013) to the data from 4 experiments, 2 with 2-choice manual responses, 1 with 4-choice manual touch screen responses, 1 with both 4-choice vocal responses, and 4-choice manual keyboard responses. Changes in the rate of information accumulation captured conflict effects for the manual-response versions, but not for the vocal-response version. Adding an extra nondecision time parameter allowed RTCON2 to account for the data patterns in the vocal-response version. However, to fully understand conflict in the vocal-response Stroop task, a model of conflict processing in the vocal word production system must be developed that would explain the additional processing time in the nondecision time parameter. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Vocalic Sounds Articulation by Selected Nigerian Television Newscasters: A Nigerian RP?

This article accounts for the articulation of vocalic sounds in the speech of selected Nigerian television newscasters. The work discusses how Nigerian newscasters who present network news to Nigerians and the international community articulate vocalic sounds. It argues that their articulation of vowels represents an acrolectal variety of spoken Nigerian English which Jowitt (2015) refers to as “Nigerian RP,” an endonormative model for spoken Nigerian English. Since previous studies on the vocalic system of Nigerian English were done over a decade or two decades ago, there is need for a follow-up empirical study which tracks possible developments in the variety. This article, therefore, tries to track possible developments in articulation of vocalic sounds by Nigerian newscasters within the period 2014–2017, and accounts for the various influences that shape their articulations. The paper, which adopted the acrolectal component of Ugorji’s (2010) trio lects classification, uses downloaded news broadcasts and interview sessions of thirty (30) purposively selected Nigerian television newscasters from YouTube (and tape-recorded where necessary). The data was analysed perceptually, acoustically and statistically. Tokens of occurrence of sound articulations were counted and presented in tables using simple percentage. The data shows that the realisations of monophthongs by 100% of the newscasters largely correspond to RP. The closing diphthongs, /eɪ/, /aɪ/, /aʊ/, /ɔɪ/, were phonemically realised by 98% of the newscasters in the manner of RP. The diphthong, /ʊə/, was reduced to a monophthong by 45% of the selected newscasters, while /əʊ/ was realised as /oʊ/, the American equivalent of the segment, by most of the newscasters. Triphthongs, /aɪə/ and /aʊə/ were realised by 55% of the sampled newscasters in quiet and power respectively.

Acoustic structure of forest elephant rumbles: a test of the ambiguity reduction hypothesis.

Quantitative assessments of the structure of vocalizations are a fundamental prerequisite to understand a species' vocal communication system and, more broadly, the selective pressures shaping vocal repertoires. For example, to reduce ambiguity in signal interpretation in the absence of auxiliary visual cues, species in densely vegetated habitats should exhibit more discrete vocal signals than species in open habitats. To test this "ambiguity reduction hypothesis", we conducted the first quantitative assessment of the rumble vocalizations of the forest elephant. Based on 686 forest elephant rumbles recorded with autonomous acoustic recording units at four sites across Central Africa, we used model-based cluster analyses paired with subsequent evaluation of cluster-discreteness and discriminant function analyses to quantify the structure of rumbles based on 23 source- and filter-related acoustic parameters. Model-based cluster analyses suggest that rumbles can be classified into five toeight types. Similar to previous findings in savannah elephants and contrary to the ambiguity reduction hypothesis, average silhouette coefficients below 0.34 indicated that these rumble types were highly intergraded. However, discriminant function analyses predicted rumble types with at least 75% accuracy whereby the location of the minimum fundamental frequency, middle slope and peak frequency contributed most to separation between types. In line with an increasing number of studies highlighting that a distinction between discrete and graded repertoires may have little biological significance, we propose that ambiguity reduction may take place through the evolution of perceptual and cognitive mechanisms, rather than acting on vocal production.

Exploring the molecular basis of neuronal excitability in a vocal learner

BackgroundVocal learning, the ability to learn to produce vocalizations through imitation, relies on specialized brain circuitry known in songbirds as the song system. While the connectivity and various physiological properties of this system have been characterized, the molecular genetic basis of neuronal excitability in song nuclei remains understudied. We have focused our efforts on examining voltage-gated ion channels to gain insight into electrophysiological and functional features of vocal nuclei. A previous investigation of potassium channel genes in zebra finches (Taeniopygia guttata) revealed evolutionary modifications unique to songbirds, as well as transcriptional specializations in the song system [Lovell PV, Carleton JB, Mello CV. BMC Genomics 14:470 2013]. Here, we expand this approach to sodium, calcium, and chloride channels along with their modulatory subunits using comparative genomics and gene expression analysis encompassing microarrays and in situ hybridization.ResultsWe found 23 sodium, 38 calcium, and 33 chloride channel genes (HGNC-based classification) in the zebra finch genome, several of which were previously unannotated. We determined 15 genes are missing relative to mammals, including several genes (CLCAs, BEST2) linked to olfactory transduction. The majority of sodium and calcium but few chloride channels showed differential expression in the song system, among them SCN8A and CACNA1E in the direct motor pathway, and CACNG4 and RYR2 in the anterior forebrain pathway. In several cases, we noted a seemingly coordinated pattern across multiple nuclei (SCN1B, SCN3B, SCN4B, CACNB4) or sparse expression (SCN1A, CACNG5, CACNA1B).ConclusionThe gene families examined are highly conserved between avian and mammalian lineages. Several cases of differential expression likely support high-frequency and burst firing in specific song nuclei, whereas cases of sparse patterns of expression may contribute to the unique electrophysiological signatures of distinct cell populations. These observations lay the groundwork for manipulations to determine how ion channels contribute to the neuronal excitability properties of vocal learning systems.

CWT-Based Approach for Epoch Extraction From Telephone Quality Speech

Epochs are the instants of significant excitation to vocal tract system. Existing methods can extract epochs accurately from clean speech signals. However, identification of epoch locations from band-limited telephonic speech is challenging due to the attenuation of fundamental frequency component and degradation caused by channel effect. This letter proposes an epoch extraction method that can accurately extract epochs from clean as well as telephonic speech signals. In the proposed method, the significant impulse-like discontinuities are extracted directly from the speech signal using continuous wavelet transform. The performance of the proposed method is evaluated using three speakers, namely, SLT, BDL, and JMK from CMU Arctic database. The clean speech is simulated using G.191 software tools to obtain telephonic speech. Experimental results show that the epoch identification rate of proposed method is significantly better than the state-of-the-art methods for the telephone quality speech.

Speech and language processing for assessing child–adult interaction based on diarization and location

Understanding and assessing child verbal communication patterns is critical in facilitating effective language development. Typically speaker diarization is performed to explore children’s verbal engagement. Understanding which activity areas stimulate verbal communication can help promote more efficient language development. In this study, we present a two-stage children vocal engagement prediction system that consists of (1) a near to real-time, noise robust system that measures the duration of child-to-adult and child-to-child conversations, and tracks the number of conversational turn-takings, (2) a novel child location tracking strategy, that determines in which activity areas a child spends most/least of their time. A proposed child–adult turn-taking solution relies exclusively on vocal cues observed during the interaction between a child and other children, and/or classroom teachers. By employing a threshold optimized speech activity detection using a linear combination of voicing measures, it is possible to achieve effective speech/non-speech segment detection prior to conversion assessment. This TO-COMBO-SAD reduces classification error rates for adult-child audio by 21.34% and 27.3% compared to a baseline i-Vector and standard Bayesian Information Criterion diarization systems, respectively. In addition, this study presents a unique location tracking system adult-child that helps determine the quantity of child–adult communication in specific activity areas, and which activities stimulate voice communication engagement in a child–adult education space. We observe that our proposed location tracking solution offers unique opportunities to assess speech and language interaction for children, and quantify the location context which would contribute to improve verbal communication.

A Comparative Analysis of the Albanian and British English Vowel System

Analyzing the complexity of the articulatory process of the vowels in Albanian and English language is of crucial importance in distinguishing their unique phonetic and phonological properties. The standard Albanian vocalic system includes seven vowels, unlike the standard British English vowel system which consists of five vowels. Drawing points of similarity and differentiation between the vowel systems of the two languages requires detailed analysis regarding the degree of opening and the position of the tongue in the vowel tract. Therefore the purpose of this paper is to highlight differences and similarities of the vowel system (monophthongs) between standard Albanian language and British English. The seven Albanian vowels considerably differ from their five English counterparts, not only by their degree of opening but even by their placement concerning the horizontal movement of the tongue, which can be observed by examining the two vowel charts of both languages. The Albanian vowel system is displayed through a triangle, meanwhile the English vowel system is a schematic arrangement of vowels into a quadrilateral.Thus analyzing their properties by using a comparative approach regarding vowels articulation in both languages would help in generating a clear picture of their common and distinguishing characteristics.

Correlating an Ambulatory Voice Measure to Electrodermal Activity in Patients with Vocal Hyperfunction.

We investigate the connection between the autonomic nervous system and the voice in patients with vocal hyperfunction and healthy-control groups. We present a methodology and preliminary results of two multi-modal measurement streams that capture this relationship. Subjects were instrumented for daily, ambulatory collection of their voice and wrist-based electrodermal activity. Measures of vocal function (e.g., fundamental frequency) were computed, as well as measures of autonomic function (e.g., skin conductance response). Spearman correlation coefficients were calculated to measure the relationship between vocal and autonomic function over sliding windows throughout each observation day. We found preliminary evidence that patients with a subtype of vocal hyperfunction (non-phonotraumatic vocal hyperfunction) exhibit a coupling between the autonomic nervous system and the vocal system. Understanding how the autonomic nervous system interacts with the voice may provide new insights into the etiology/pathophysiology of vocal hyperfunction and improve prevention, diagnosis and treatment of these disorders.

Investigating the potential for call combinations in a lifelong vocal learner

AbstractThe ability for humans to create seemingly infinite meaning from a finite set of sounds has likely been a critical component in our success as a species, allowing the unbounded communication of information. Syntax, the combining of meaningful sounds into phrases, is one of the primary features of language that enables this extensive expressivity. The evolutionary history of syntax, however, remains largely debated, and it is only very recently that comparative data for syntax in animals have been revealed. Here, we provide further evidence for a structural basis of potential syntactic‐like call combinations in the vocal communication system of a group‐living songbird. Acoustic analyses indicate that Western Australian magpies (Gymnorhina tibicen dorsalis) structurally combine generic alarm calls with acoustically distinct alert calls to produce an alarm alert sequence. These results are distinct from previous examples of call combinations as, to our knowledge, evidence for this capacity is yet to be demonstrated in the natural communication of a non‐human species that is capable of vocal learning throughout life. These findings offer prospects for experimental investigation into the presence and function of magpie call combinations, extending our understanding of animal vocal complexity.

ANALISIS KOMPARATIF ANTARA BAHASA JAMEE (ACEH) DAN BAHASA MINANGKABAU (BUKITTINGGI)

The problems in this study are the differences in phonology, lexical, morphology, and syntactic structure between Jamee (Aceh) and Minangkabau (Bukittinggi). The aim of this research is to know the difference of phonology, lexical, morphology, and syntactic structure between Jamee language and Minangkabau Bukittinggi language. The method used in this research was descriptive with qualitative approach. Data were collected by observation, interview, and documentation techniques. The data sources in this research were 5 speakers of Jamee language and 5 speakers of Minangkabau Bukittingi language. the data analysis procedures were data selection, data classification, and data presentation. The results of research in this article phonological differences, there were / ɛ / and / ɔ / in vocal system of Jamee, / a / while vocal system of Minangkabau Bukittinggi language and Jamee / ɣ / or / R / language consonant system, while Minangkabau Bukittinggi language / r /, then there were pronunciation differences include single vowels, double vowels, and consonants. These differences consist of nouns, adjectives, verbs, and adverbs. For affixation, the difference lies in the insertion (infix) -al-, -ar- in Jamee and -am-, -um- in Minangkabau Bukittinggi. The suffixes (suffixes) -en, -ken in Jamee, -in the Minangkabau language of Bukittinggi, and the ends (confix) there were me-ken, me-en, ma-kan, ma-an in Minangkabau language Bukittinggi, except prefixes. The prefixes of the two languages have similarity. The differences was also seen from word classification in verbs, nouns, adjectives, numerelia, and adverbs. In terms of the type of word repetition there was no difference only in the form of words or basic words only, while the sentence structure of the two languages have in similarities.

A feature geometric approach to Bondu-so vowel harmony

Bondu-so (Dogon; Mali) vowel harmony exhibits both typologically and theoretically interesting properties. The language’s vocalic system displays surface patterns that implicate a ten-vowel system with an underlying [ATR] contrast at three vowel heights that is not immediately apparent given only mid vowels maintain an [ATR] contrast on the surface. The current paper presents previously unaccounted for data that show alternations associated with Bondu-so vowel harmony correlate not only with the [ATR] specification of a given root vowel, but also with properties of the root-final consonant. We appeal to a combination of featural and prosodic licensing to analyze these outcomes and do so in a modified version of the Parallel Structures Model of feature geometry. The PSM framework has been employed in studies of consonant assimilation and consonant-vowel interaction, but to our knowledge, the current paper is the first to extend it specifically to the analysis of vowel harmony.

Precise vocal timing needs cortical control.

The evolution of vocal communication systems is investigated in a rodent model

Combinatoriality in the vocal systems of nonhuman animals.

A key challenge in the field of human language evolution is the identification of the selective conditions that gave rise to language's generative nature. Comparative data on nonhuman animals provides a powerful tool to investigate similarities and differences among nonhuman and human communication systems and to reveal convergent evolutionary mechanisms. In this article, we provide an overview of the current evidence for combinatorial structures found in the vocal system of diverse species. We show that considerable structural diversity exits across and within species in the forms of combinatorial structures used. Based on this we suggest that a fine-grained classification and differentiation of combinatoriality is a useful approach permitting systematic comparisons across animals. Specifically, this will help to identify factors that might promote the emergence of combinatoriality and, crucially, whether differences in combinatorial mechanisms might be driven by variations in social and ecological conditions or cognitive capacities. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Linguistics > Evolution of Language.

A Pilot Quantitative Evaluation of Early Life Language Development in Fragile X Syndrome.

Language delay and communication deficits are a core characteristic of the fragile X syndrome (FXS) phenotype. To date, the literature examining early language development in FXS is limited potentially due to barriers in language assessment in very young children. The present study is one of the first to examine early language development through vocal production and the language learning environment in infants and toddlers with FXS utilizing an automated vocal analysis system. Child vocalizations, conversational turns, and adult word counts in the home environment were collected and analyzed in a group of nine infants and toddlers with FXS and compared to a typically developing (TD) normative sample. Results suggest infants and toddlers with FXS are exhibiting deficits in their early language skills when compared to their chronological expectations. Despite this, when accounting for overall developmental level, their early language skills appear to be on track. Additionally, FXS caregivers utilize less vocalizations around infants and toddlers with FXS; however, additional research is needed to understand the true gap between FXS caregivers and TD caregivers. These findings provide preliminary information about the early language learning environment and support for the feasibility of utilizing an automated vocal analysis system within the FXS population that could ease data collection and further our understanding of the emergence of language development.

Urotensin-related gene transcripts mark developmental emergence of the male forebrain vocal control system in songbirds

Songbirds communicate through learned vocalizations, using a forebrain circuit with convergent similarity to vocal-control circuitry in humans. This circuit is incomplete in female zebra finches, hence only males sing. We show that the UTS2B gene, encoding Urotensin-Related Peptide (URP), is uniquely expressed in a key pre-motor vocal nucleus (HVC), and specifically marks the neurons that form a male-specific projection that encodes timing features of learned song. UTS2B-expressing cells appear early in males, prior to projection formation, but are not observed in the female nucleus. We find no expression evidence for canonical receptors within the vocal circuit, suggesting either signalling to other brain regions via diffusion or transduction through other receptor systems. Urotensins have not previously been implicated in vocal control, but we find an annotation in Allen Human Brain Atlas of increased UTS2B expression within portions of human inferior frontal cortex implicated in human speech and singing. Thus UTS2B (URP) is a novel neural marker that may have conserved functions for vocal communication.