Number Of Formants Research Articles

Processing group delay spectrograms for study of formant and harmonic contours in speech signals.

This paper deals with study of formant and harmonic contours by processing the group delay (GD) spectrograms of speech signals. The GD spectrum is the negative derivative of the phase spectrum with respect to frequency. Recent study shows that the GD spectrogram can be obtained without phase wrapping. Formant frequency contours can be observed in the display of the peaks of the instantaneous wideband equivalent GD spectrogram, derived using the modified single frequency filtering (SFF) analysis of speech signals. Harmonic frequency contours can be observed in the display of the peaks of the instantaneous narrowband equivalent GD spectrogram, derived using the modified SFF analysis of speech signals. For synthetic speech signals, the observed formant contours match the ground truth formant contours from which the signal is derived. For natural speech signals, the observed formant contours match approximately with the given ground truth formant contours mostly in the voiced regions. The results are illustrated for several randomly selected utterances from the TIMIT database. While this study helps to observe the contours of formants in the display, automatic extraction of the formant frequencies needs further processing, requiring logic for eliminating the spurious points, without forcing the number of formants.

Spin Hall effect of Laguerre-Gaussian beams in PT symmetric metamaterials

Spin Hall effect (SHE) of Laguerre-Gaussian (LG) beams reflected and transmitted in parity-time (PT) symmetric metamaterials are investigated near the coherent-perfect-absorption (CPA)-laser point and exceptional points (EPs). The numerical results show that large transverse shifts occur at the CPA-laser point regardless of the incident direction. But at EPs, the SHE increases at one side and disappears at the other side, thus achieving the intense SHE of the reflected light beams at the specified side incidence. In addition, it is found that Bragg oscillation can be generated by increasing the period number of PT symmetric metamaterial layers, thus increasing the number of formants in transverse displacement. In particular, the transverse shift peaks of the transmitted beams merge into a positive peak when the incident angle is close to 90∘ and does not change basically with the increasing of Im(ɛ), which can also be considered as a strong tolerance to the variation of Im(ɛ). This feature is expected to realize a new type of optoelectronic devices with anti-interference performance. These results provide a feasible path for the modulation of spin Hall effect of light (SHEL) and provide the possibility for the development of new nanophotonic devices.

Vocal Tract Length Estimation Using Accumulated Means of Formants and Its Effects on Speaker-Normalization

Differences in vocal tract lengths (VTLs) in individual speakers cause variations in acoustic features of phonemes. In this paper, a simple method to estimate speaker-specific VTLs and to quantitatively evaluate some speaker-normalization effects of the VTLs is proposed. We employed accumulated means of formant trajectories to estimate the VTLs of speakers ranging from children to adults. For the formant estimation, the inverse-filter control (IFC) system was used. In the system, the decision of analysis order, which means number of formants to be estimated, is automated. Moreover, to evaluate the speaker-normalization effect of VTLs, we proposed the data reduction method, which can reasonably find dense areas of ellipses from distributions in the formant space. Using these ellipse areas, we evaluated the three normalization effects of VTLs: normalization by the mean of all VTLs as the standard, by speaker-categorical means of VTLs, and by individual VTLs. The area reduced from the standard area of the original data by 39.5% and 46.6% in the case of the categorical means and individual VTLs, respectively. As a result, our proposed method was used to provide a “normalized vowel map (NVM)” that visualizes universal vowel-distributions as a core image of linguistic information. Finally, we compared the estimated VTLs with those by another method based on magnetic resonance imaging (MRI) data, using the proposed methods.

Imiona i derywaty odimienne używane na polskiej Warmii w XIX wieku

The article presents first names and derivatives derived from first names, used in families in Warmia in the 19th century. The material was gathered from the work of W. Barczewski, Kiermasy in Warmia. Names in Warmian families were passed down from generation to generation and given in accordance with family tradition.
 The selection of names was scarce. First names were rare in common circulation, more often short names and deminutive-hypocoristic forms created with a small number of formants were used. The number of diminutive or playful female names was limited. These were created by name derivatives: Luca, Jewka, Lucka, Nulka, Baśka, Basia, Barwuchna, Dośka, Waleśka, Elzka, Joanka, Finka, Katrynka, Kaśka, Marychna, and Staśka. Of the male names, Barczewski certified ten names in basic forms: Jakub, Andrzej, Stefan, Klement, Michał, Maciej, Marcin, Joachim, Wojciech, Kazimierz and derivative hypocorrisms and deminutive forms: Janek, Michałek, Maciek, Kuba, Kubal, Kubalek, Kaźnirek, Wojtek, Jędrysek, Józefek, Wiktorek, Frąck, Matys. Respect for adults was expressed through full names, whereas children were addressed with deminutive-hypocorristic forms, and emotionally-oriented forms.

Variation of Formant Frequency with Nepalese Vowels

The regions of speech spectrum in which the frequency corresponds to relatively large amplitude are known as formants. For any vocalic sounds, number of formants may occur in the frequency range 0 to 4000 Hz. The formant frequencies of speech sounds are directly depending up on the shape and size of vocal tract. The aim of study was to study the variation of formant frequency with Nepalese vowels. Ten Nepalese vowels word in initial position /VC/ as spoken three times by 10 male and 10 female Nepali speakers were recorded in system in the free field of partially acoustically treated room. PRRAT software is used to digitize and analyze the data. Linear predictive coding (LPC) spectra were obtained for each of vowels and formant frequencies were measured. By plotting curve between formant frequencies and vowels, explain their variation.

Forensic Speaker Verification Using Ordinary Least Squares.

In Brazil, the recognition of speakers for forensic purposes still relies on a subjectivity-based decision-making process through a results analysis of untrustworthy techniques. Owing to the lack of a voice database, speaker verification is currently applied to samples specifically collected for confrontation. However, speaker comparative analysis via contested discourse requires the collection of an excessive amount of voice samples for a series of individuals. Further, the recognition system must inform who is the most compatible with the contested voice from pre-selected individuals. Accordingly, this paper proposes using a combination of linear predictive coding (LPC) and ordinary least squares (OLS) as a speaker verification tool for forensic analysis. The proposed recognition technique establishes confidence and similarity upon which to base forensic reports, indicating verification of the speaker of the contested discourse. Therefore, in this paper, an accurate, quick, alternative method to help verify the speaker is contributed. After running seven different tests, this study preliminarily achieved a hit rate of 100% considering a limited dataset (Brazilian Portuguese). Furthermore, the developed method extracts a larger number of formants, which are indispensable for statistical comparisons via OLS. The proposed framework is robust at certain levels of noise, for sentences with the suppression of word changes, and with different quality or even meaningful audio time differences.

Praat을 이용한 아동 포먼트 자동 세팅 스크립트 구현*

This study introduces an automated Praat script allowing optimal formant analysis for children’s vowels. Using Burg’s algorithm in Praat, formants can be extracted by setting the maximum formant value and the number of formants. The optimal formant setting was determined by identifying the two conditions, F1 and F2, with minimum standard deviations. When applying the optimal formant setting determined by the script, the results of normality tests were not significant among all vowels except /e/ for the maximum formant value, and among the vowels /a/, /e/, /i/, /o/, /u/ and /ʌ/ for the number of formants. This indicates that when analyzing the formants of children’s vowel sounds, the unilateral application of a parameter setting (the maximum formant value and the number of formants) to all vowels is problematic. The performance of the optimal formant setting script was evaluated along with 3 different algorithm in order to determine whether it properly extracts formants for children’s vowels. To this end, Korean monophghongs of 6-year-old children were collected and the Praat scripts were applied to the data. Resultant Formant plots and statistical analysis showed that optimum_script and qtone_script, which links to the perceptual unit, performed very well in formant extraction compared to the remaining 2 scripts.

Pogranicze polsko-wschodniosłowiańskie w świetle nazw terenowych na przykładzie gminy Wisznice

The article is an attempt to conduct a semantic and structural analysis of Wisznice community’s microtoponyms. As a result, it was shown that the topographical names are the majority, followed by cultural and possessive names. The primary names constitute the majority in the group of topographical and cultural names. The appellatives, concerning properties of geographical environment, belong to them. Simultaneously, they are appellative base of analyzed local names. In the group of secondary names, the topographical and possessive names are the most numerously represented, less often cultural ones. The big number of formants is typical for this group of names Key.

Informational masking of speech by time-varying competitors: Effects of frequency region and number of interfering formants.

This study explored the extent to which informational masking of speech depends on the frequency region and number of extraneous formants in an interferer. Target formants-monotonized three-formant (F1+F2+F3) analogues of natural sentences-were presented monaurally, with target ear assigned randomly on each trial. Interferers were presented contralaterally. In experiment 1, single-formant interferers were created using the time-reversed F2 frequency contour and constant amplitude, root-mean-square (RMS)-matched to F2. Interferer center frequency was matched to that of F1, F2, or F3, while maintaining the extent of formant-frequency variation (depth) on a log scale. Adding an interferer lowered intelligibility; the effect of frequency region was small and broadly tuned around F2. In experiment 2, interferers comprised either one formant (F1, the most intense) or all three, created using the time-reversed frequency contours of the corresponding targets and RMS-matched constant amplitudes. Interferer formant-frequency variation was scaled to 0%, 50%, or 100% of the original depth. Increasing the depth of formant-frequency variation and number of formants in the interferer had independent and additive effects. These findings suggest that the impact on intelligibility depends primarily on the overall extent of frequency variation in each interfering formant (up to ∼100% depth) and the number of extraneous formants.

Effects of frequency region and number of formants in an interferer on the informational masking of speech

This study explored whether the extent of informational masking depends on the frequency region and number of formants in an interferer. Target formants—monotonized three-formant analogues of natural sentences—were presented monaurally, with the target ear assigned randomly on each trial. Interferers were presented contralaterally. In experiment 1, single-formant interferers were created using the time-reversed F2 frequency contour and constant amplitude, RMS-matched to F2. Interferer center frequency was matched to that of F1, F2, or F3, while maintaining the extent of formant-frequency variation (depth) on a log scale. In experiment 2, the interferer comprised either one formant (F1) or all three, created using the time-reversed frequency contours of the corresponding targets and RMS-matched constant amplitudes. Including the higher formants had little effect on interferer intensity. Interferer formant-frequency variation was scaled to 0%, 50%, or 100% of the original depth. Adding an interferer lowered target intelligibility; frequency region had relatively little effect, but increasing depth of formant-frequency variation and number of formants had independent and additive effects. This suggests that the impact on intelligibility depends primarily on the number of formants and the overall extent of frequency variation in the interferer, not on any particular frequency region. [Work supported by ESRC.]

Investigating the use of formant frequencies in listener judgments of speaker size

The formant-pattern present in a given vowel sound will be determined by the vocal-tract length (VTL) of the speaker as well as by phoneme-specific information. Although human listeners tend to associate lower formant-frequencies with larger speakers, it is unclear whether they are responding to VTL information in speech sounds, or simply responding to the formant-pattern present in the sound. In this experiment listeners were presented with pairs of synthetic vowels from the set of (/i æ ʊ/), which could differ on the basis of simulated VTL and vowel category, within-pair. Listeners were divided into groups based on the number of formants contained by stimulus vowels (2, 3, 4, and 5-formant vowel groups). For each trial, listeners were asked to indicate which vowel sounded like it had been produced by a taller speaker. Results indicate that listeners do not rely solely on VTL cues when making speaker-size judgments, and that they exhibit biases towards selecting given phonemes as taller, even when contrary to the VTL differences between the voices. Furthermore, the higher formants (up to F5) are used by listeners when making speaker-size judgments, though not in a manner consistent with VTL-based speaker-size judgments.

Dynamic Speech Spectrum Representation and Tracking Variable Number of Vocal Tract Resonance Frequencies With Time-Varying Dirichlet Process Mixture Models

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, we propose a new approach for dynamic speech spectrum representation and tracking vocal tract resonance (VTR) frequencies. The method involves representing the spectral density of the speech signals as a mixture of Gaussians with unknown number of components for which time-varying Dirichlet process mixture model (DPM) is utilized. In the resulting representation, the number of formants is allowed to vary in time. The paper first presents an analysis on the continuity of the formants in the spectrum during the speech utterance. The analysis is based on a new state space representation of concatenated tube model. We show that the number of formants which appear in the spectrum is directly related to the location of the constriction of the vocal tract (i.e., the location of the excitation). Moreover, the disappearance of the formants in the spectrum is explained by “uncontrollable modes” of the state space model. Under the assumption of existence of varying number of formants in the spectrum, we propose the use of a DPM model based multi-target tracking algorithm for tracking unknown number of formants. The tracking algorithm defines a hierarchical Bayesian model for the unknown formant states and the inference is done via Rao–Blackwellized particle filter. </para>

Linear scaling of vowel-formant ensembles (VFEs) in consonantal contexts

There are familiar terms such as “contour” and “trajectory” to refer to a vowel formant frequency as a function defined on the time axis, but there is no readily understood term for the analogous idea of how a formant behaves on the “vowel axis”. For this we introduce the concept of a vowel-formant ensemble (VFE) as the set of values realized for a given formant (e.g., F 2) in going from vowel to vowel among a speaker's vowel phonemes for a fixed time frame in a fixed CVC context. The VFE affords a simple description of our development: we observe that D.J. Broad and F. Clermont's [J. Acoust. Soc. Am. 81 (1987) 155] formant-contour model is a linear function of its vowel target and that as a consequence all its VFEs for a given speaker and formant number are linearly scaled copies of one another. Are VFEs in actual speech also linearly scaled? To show how this question can be addressed, we use F 1 and F 2 data on one male speaker's productions of 7 Australian English vowels in 7 CVd contexts, with each CVd repeated 5 times. Our hypothesized scaling relation gives a remarkably good fit to these data, with a residual rms error of only about 14 Hz for either formant after discounting random variations among repetitions. The linear scaling implies a type of normalization for context which shrinks the intra-vowel scatter in the F 1F 2 plane. VFE scaling is also a new tool which should be useful for showing how contextual effects vary over the duration of the syllable's vocalic nucleus.

Mice and humans perceive multiharmonic communication sounds in the same way

Vowels and voiced consonants of human speech and most mammalian vocalizations consist of harmonically structured sounds. The frequency contours of formants in the sounds determine their spectral shape and timbre and carry, in human speech, important phonetic and prosodic information to be communicated. Steady-state partitions of vowels are discriminated and identified mainly on the basis of harmonics or formants having been resolved by the critical-band filters of the auditory system and then grouped together. Speech-analog processing and perception of vowel-like communication sounds in mammalian vocal repertoires has not been demonstrated so far. Here, we synthesize 11 call models and a tape loop with natural wriggling calls of mouse pups and show that house mice perceive this communication call in the same way as we perceive speech vowels: they need the presence of a minimum number of formants (three formants-in this case, at 3.8 + 7.6 + 11.4 kHz), they resolve formants by the critical-band mechanism, group formants together for call identification, perceive the formant structure rather continuously, may detect the missing fundamental of a harmonic complex, and all of these occur in a natural communication situation without any training or behavioral constraints. Thus, wriggling-call perception in mice is comparable with unconditioned vowel discrimination and perception in prelinguistic human infants and points to evolutionary old rules of handling speech sounds in the human auditory system up to the perceptual level.

Fourier spectra and formant patterns of German vowels produced at F0 of 70–850 Hz

Previous studies of vowel synthesis and of natural vowels have indicated: (1) a correlation between the lower formants and F0 for F0&amp;gt;175 Hz; (2) intelligibility and spectral differences of vowels with high F0&amp;gt;500 Hz; (3) severe methodological problems of formant frequency estimation for F0&amp;gt;300 Hz; (4) formant number alterations (appearance of different numbers of relevant formants for one vowel); (5) formant pattern ambiguity (appearance of the same formant pattern for different vowels). The purpose of this study was to replicate these findings. A large sample of the German vowels /i,y,e,o/,ε,■,o,u/ produced in isolation as well as in CVC context was investigated. There were 18 674 recordings made of 35 men, 44 women, and 20 children. Isolated vowels were produced at different levels of F0, and with different intensities. A listening test was performed. Fourier spectra, LPC spectra and spectral constancy were analyzed. The results strongly support the five indications mentioned. In particular, for isolated vowel sounds the correlation between the formants and F0, the appearance of ‘‘one-formant back vowels’’ (only one apparent formant &amp;lt;2 kHz), and the formant pattern ambiguity for nonadjacent vowels proved to be very pronounced. Consequences for normalization approaches are discussed.

Interspecific versus intraspecific variation in alarm call vocalization among two species of capuchin monkey.

Inter‐ and intraspecific variation in alarm calls were compared for two species of free‐ranging capuchin monkey: the wedge‐capped capuchin (Cebus olivaceus) and the white‐faced capuchin (Cebus capuchinus). Alarm calls in each case were made in the presence of the same predator, a boa constrictor. Vocalizations (n=40) were compared for commonly examined acoustic parameters (e.g., signal duration, frequency, and amplitude variables), as well as for vocal features found to be acoustic cues to the monkeys [e.g., bandwidth of dominant formant; change in frequency of the dominant formant (see Norris, 4aAB3)]. Additionally, correlations of spectrograms were performed using CANARY. Interspecific variability was found to be significantly greater than intraspecific variability for signal duration (F=45.30;p<0.0001), maximum frequency (F=8.52; p<0.0059), and formant number (F=10.32;p<0.0027). However, interspecific variability of calls was not significant for any of the acoustic parameters found to be used as perceptual cues for the two species. The evolutionary and ecological significance of these findings will be discussed.

FO-dependence, number alteration, and non-systematic behaviour of the formants in German vowels.

In acoustic theory, formant pattern differences within one vowel identify are related to differences in the speaker groups or in the types of vocalization. Yet, studies of vowel synthesis indicate that formant patterns can also vary strongly in relation either to pitch or to formant number alterations. Within this study, natural vocalizations of nine German vowels were investigated with regard to different formant patterns representing the same vowel identity, apart from differences in speaker groups and vocalization types. The results show i) FO-dependence of the lower formants < 1.5-2 kHz; ii) occurrence of natural one-formant back and two-formant front vowels; iii) a non-systematic relationship between FO and the formants, and a non-systematic relationship between formant patterns of different formant numbers. The implications for psychophysics, physiology and perception of speech are discussed.

Determining vocal tract shape with small section length given only a few formants

Vocal tract shape made up of cylindrical sections of equal length can be determined given the formant data of vowel sounds; the number of sections equals twice the number of formants. For an adult male speaker, use of four formants, results in a large section length of 2.125 cm. If section length of 0.5 cm is desired, 17 formants have to be specified which appears impractical. A method for obtaining vocal tract shape with small section lengths, given only a few lower formants (up to fourth or fifth) is presented. For vocal tract of M sections, only the lower M/2 formants are independent and upper formants are constrained by the lower formants. This constraint gives unrealistic locations for the upper formants. One method for predicting the upper formants would be to use those of a uniform tube of same length as that of the vocal tract. For a desired section length (say 0.5 cm), the required formants (say, 17) can be specified by using the given lower formants (say, four) and predicted upper formants (say, from 5 to 17). Validation of the method using x-ray data and simulated vocal tract shapes is presented.

Processing of stop-vowel syllables by normal and language-impaired children

It has been claimed that language-learning disordered children have impaired rapid-rate auditory processing. One manifestation is the failure to identify stop-vowel syllables; another less fine-grained discrimination of stop-vowel syllables. In the present study, 20 language-impaired (LI) and 20 normal (LN) children (6 to 10 years) attempted to identify /ba/–/da/ syllables within an adaptive paradigm. When they failed to do so, they were given a change/no change discrimination task with these stimuli. Formant transition duration (FTD) ranged from 80 to 40 ms. The syllable pairs had either five or two formants. As in previous studies, LI children failed the identification task, even for syllables of 80-ms FTD, significantly more often than LN. They were able to discriminate the syllables. Number of formants was not a significant variable. A subgroup of LI and LN children were subsequently asked to produce the test syllables. In both groups, children unable to produce the syllables had difficulty in identify them. The reverse was not true. Perception difficulties were not predictive of production errors. [Work supported by NIH.]

Formant Movement and Formant Number Alteration With Rising Fo in Real Vocalizations of the German Vowels [U:], [O:] and [A:

Production theory explains vowel sounds by formants in terms of a resonance pattern of the vocal tract. In perception theory normalization must also be undertaken because of different formant values for one vowel category, as found in comparisons of men, women and children, and in studies of sung vowels and of synthesized vowel sounds. Synthesis indicates a dependence of the formants on FO. Therefore, the question arises whether the formant pattern is directly related to FO when studied in real vocalizations. This study presents: a. a method to determine formant movement in real vocalizations for all FO, and b. the results of spectral and LPC analysis of the three German vowels [u:], [o:] and [a:] in real vocalizations. The need for formant movement with altering FO, as well as a change in the number of formants with altering FO, is demonstrated. The implications of these results for normalization in the description of the physics of the vowel sound wave are discussed.