Showing papers on "Fundamental frequency published in 1984"

Analysis of voice fundamental frequency contours for declarative sentences of Japanese

Abstract: A model for the generation of fundamental frequency contours (F0 contours) of spoken, sentences is presented for the purpose of elucidating the relationship between the sentence F0 contour and the linguistic and non-linguistic information. It is based on a quantitative formulation of the process whereby the logarithmic fundamental frequency is controlled in proportion to the sum of two components corresponding respectively to the effects of phrase and accent. The model's parameters were determined to give the best approximation to an observed F0 contour on the basis of the mean squared error. Analysis of natural utterances of various declarative sentences of Japanese revealedthat the model can generate close approximations to observed F0 contours from a set of discrete commands and a small number of parameters. The extracted parameters were found to be closely related to linguistic factors and factors constituting thenaturalness of speech. These results provide a means for generating natural F0 contours from a small set of parameters and rules for synthesis.

Speech coding in the auditory nerve: I. Vowel-like sounds

Abstract: Discharge patterns of auditory‐nerve fibers in anesthetized cats were recorded in response to a set of nine steady‐state, two‐formant vowels presented at 60 and 75 dB SPL. The largest components in the discrete Fourier transforms of period histograms were almost always harmonics of the vowel fundamental frequency that were close to one of the formant frequencies, the fundamental frequency or the fiber characteristic frequency (CF). For any fiber, the position of its CF relative to the formant frequencies (F1 and F2) appears to determine which of these components dominates the response. Specifically, the response characteristics of the tonotopically arranged array of fibers can be described in terms of five CF regions: (1) a low‐CF region below F1 in which the largest response components are the harmonics of the fundamental frequency closest to CF; (2) a region centered around CF = F1 in which the first formant and its harmonics are the largest components; (3) an intermediate region between F1 and F2 with prominent components at both the fiber CF and the fundamental frequency; (4) a region centered around CF = F2 in which harmonics close to the second formant are the largest for frequencies above the fundamental; and (5) a high‐CF region in which response spectra tend to show broad, multiple peaks at the formant and fundamental frequencies. These CF regions are related to the phonetic descriptions of vowels. For example, the extent of the low‐CF region is largest for ‘‘open’’ vowels (which have a high F1), and the intermediate region is distinct only for ‘‘spread’’ vowels for which F1 and F2 are more than 1.5–2 octaves apart. For all vowels, response activity for the majority of fibers is concentrated near the formant frequencies, in contrast to responses to broadband noise for which components near CF are dominant.

Multispacecraft observations of the harmonic structure of Pc 3–4 magnetic pulsations

Abstract: Harmonically related Pc 3-4 pulsations (7-100 mHz) are observed simultaneously by the three geosynchronous satellites ATS 6, SMS 1, and SMS 2, which are separated 20 deg from one another. At a given instant the frequency of the same harmonic is different from one spacecraft to another and each spacecraft observes a decrease in the fundamental frequency as it moves from morning (15 mHz) to afternoon (10 mHz). This frequency behavior is explained in terms of standing Alfven waves, for which the frequency is determined by the local magnetic field and plasma density. Occurrence of harmonic Pc 3-4 waves only during daytime hours (0400-2000 LT) and their frequency characteristics suggest a broadband energy source located on the dayside. Possible azimuthal wave number m and azimuthal phase velocity V(phi) of the second through fourth harmonics are determined from an unusual interval during which identical harmonic frequencies were observed at SMS 1 and ATS 6. Under the assumption of tailward propagation of constant-phase fronts at the same velocity for all these harmonics, V(phi) of about 1700 km/s is obtained.

Dynamic load testing of highway bridges

Abstract: Between 1958 and 1981 the Swiss Federal Laboratories for Materials Testing and Research (EMPA) performed dynamic load tests on 226 beam and slab-type highway bridges; most of them were concrete structures. Test procedures as well as measurement and data processing techniques are briefly described. As a certain degree of standardization was maintained over the years, it was possible to draw some general conclusions from the summarized test results. In particular, the relationship between fundamental frequency and maximum span is discussed as well as the measured damping values. Additionally it is shown that a highway bridge exhibits a pronounced dynamic response only if (a) its fundamental frequency lies in the same region as one of the two vehicle modes of concern and (b) the vehicle speed and pavement roughness are tuned to each other so that the corresponding vibrations of the vehicle will be excited. As a consequence, it has been proposed to define the dynamic load allowance for highway bridge traffic loads as a function of the bridge's fundamental frequency in the new Swiss Code. Taking advantage of the rapid development in the field of electronics, new data acquisition and processing methods have been introduced at EMPA in the last few years. The synchronous measurement and recording of the test vehicle's dynamic wheel loads and the bridge response is now possible as well as subsequent digital signal analysis. (Author)

Vowel Intrinsic Pitch in Connected Speech

Abstract: We investigated whether ‘intrinsic pitch’ (IP) effects occur in connected speech. Fundamental frequency differences between German high and low vowels were measured in two different experimental condi

Resonator transducer system with temperature compensation

Abstract: A method and apparatus for measuring force or other parameters and temperature. The apparatus includes an oscillator and a vibratory element, such as a quartz crystal, which is caused to resonate by the oscillator at two frequencies f1 and f2 selected from the fundamental frequency and its overtone frequencies of the vibratory element. The vibratory element is selected so that the two frequencies f1 and f2 both vary with variation in force (or other parameter) applied to the element and with variation in temperature of the element, and so that the magnitude or scale factor of variation for frequency f, is different from that for frequency f2. The apparatus also includes a detection device for detecting the frequencies f, and f2 and for producing signals representing the frequency variation of the two frequencies relative to a reference frequency, and a processor for processing the signals produced by the detector device for determining the force (or other parameter) and temperature to which the vibratory element is subjected.

On the perception of intonation from sinusoidal sentences.

Abstract: Listeners can perceive the phonetic value of sinusoidal imitations of speech. These tonal replicas are made by setting time-varying sinusoids equal in frequency and amplitude to the computed peaks of the first three formants of natural utterances. Like formant frequencies, the three sinusoids composing the tonal signal are not necessarily related harmonically, and therefore are unlikely to possess a common fundamental frequency. Moreover, none of the tones falls within the frequency range typical of the fundamental frequency of phonation of the natural utterances upon which sinusoidal signals are based. Naive subjects nevertheless report that intelligible tonal replicas of sentences exhibit unusual “vocal” pitch variation, or intonation. The present study attempted to determine the acoustic basis for this apparent intonation of sinusoidal signals by employing several tests of perceived similarity. Listeners judged the tone corresponding to the first formant to be more like the intonation pattern of a sinusoidal sentence than: (1) a tone corresponding to the second or third formant; (2) a tone presenting the computed missing fundamental of the three tones; or (3) a tone following a plausible fundamental frequency contour generated from the amplitude envelope of the signal. Additionslly, the tone reproducing the first formant pattern was responsible for apparent intonation, even when it occurred in conjunction with a lower tone representing the fundamental frequency pattern of the natural utterance on which the replica was modeled. The effects were not contingent on relative tone amplitude within the sentence replica. The case of sinusoidal sentence “pitch” resembles the phenomenon ofdominance, that is, the general salience of waveform periodicity in the region of 400-1000 Hz for perception of the pitch of complex signals.

Abnormal noise detector for inspecting gear units

Abstract: An abnormal noise detector for detecting abnormal noises produced by a gear unit with an eccentrically mounted gear is disclosed. A first embodiment comprises a microphone placed in the vicinity of a gear unit to be tested, a bandpass filter connected to the microphone which passes only a band of frequencies centered around an integral multiple of the normal fundamental frequency of the noise produced by the meshing of the gears of the gear unit, an amplitude detector which detects the amplitude of the signal from the bandpass filter, a frequency deviation detector which detects the frequency deviation of the signal from the bandpass filter, and recorders for recording the values of the signals from the amplitude detector and the frequency deviation detector as a function of time. A second embodiment comprises a microphone, a digital frequency analyzer and a central processing unit for determining whether abnormalities exist in the data produced by the digital frequency analyzer.

Active noise reduction apparatus

Abstract: Active noise reduction apparatus for reducing noise in a cabin (1), or other enclosed space, generated by an external source, wherein the noise has a fundamental frequency f0 and harmonically related frequencies f1 to fn, includes a plurality of loudspeakers (2a, 2b, 2c) and microphones (3a, 3b, 3c, 3d) distributed over the enclosed space, source frequency measurement means for measuring the frequency f0, and a signal processor (6) connected to receive and analyse input signals from the microphones and from the source frequency measurement means, and wherein the signal processor is arranged to output signals f0 to fn in antiphase with the input signals so as to minimise sound pressure levels in the enclosed space.

Integrated oscillator antenna for low power, low harmonic radiation

Abstract: A low-power transmitter for garage door operator systems and the like wherein harmonics of the fundamental frequency are suppressed by class A or AB oscillator operation and fundamental radiation is enhanced by way of a combined inductor/radiator having conductive printed circuit extrusions on the ends thereof to effectively form a center-fed dipole antenna.

Optimal Forms of Shallow Shells With Circular Boundary, Part 1: Maximum Fundamental Frequency

Abstract: Thin, shallow, elastic shells with given circular boundary are considered. We seek the axisymmetric shell form which maximizes the fundamental frequency of vibration. The boundary conditions, material, surface area, and uniform thickness of the shell are specified. We employ a bimodal formulation and use an iterative procedure based on the optimality condition to obtain optimal forms. Results are presented for clamped and simply supported boundary conditions. For the clamped case, the optimal forms have zero slope at the boundary. The maximum fundamental frequency is significantly higher than that for the corresponding spherical shell if the boundary is clamped, but only slightly higher if it is simply supported.

The Integration of HVDC Subsystems into the Harmonic Power Flow Algorithm

Abstract: This paper is an extension of recent work done in harmonic power flow studies. The extension is inclusion of HVDC subsystems. An example using six pulse converters is given. Also, a simplification to the harmonic power flow algorithm is presented based on the accuracy of the fundamental frequency solution in the absence of nonlinear loads.

The influence of temporal cues on the strength of periodicity pitches

Abstract: Three different waveforms were generated from the same component frequencies by setting the phase of the components so they were either homophasic (all component sinusoids start at 0°), diphasic (sinusoids alternate between −45° and + 45°), or heterophasic (starting phase randomly selected). Listeners were asked to rate the saliency of all periodicity pitches they could detect in stimuli which contained 12 or more components at frequencies above the region where pitches were perceived. A major finding was that the highest ratings of fundamental frequency ( f1) pitch ‘‘strength’’ were always obtained for homophasic waveforms, which among the test stimuli have the most abrupt envelope fluctuations. In contrast, diphasic and heterophasic waveforms, which have smoother envelopes, yielded lower pitch strength estimates at f1 and higher ratings two octaves above the fundamental. These data indicate that information concerning the stimulus waveform envelope influences the relative prominence of competing pitches evoked by periodicity pitch stimuli. However, no one‐to‐one correspondence between pitch and waveform periodicity is apparent.

Synthesis by rule of voice fundamental frequency contours of spoken Japanese from linguistic information

Abstract: A number of utterance samples of complex sentences of Japanese were analyzed using the model for the process of fundamental frequency contour generation, with special emphasis on the relationship between a fundamental frequency contour and its underlying lexical, syntax and semantic information. Phrase commands of the model were found to be roughly classified into three groups according to the level of corresponding node of the syntactic tree of a sentence, while accent commands were found to be roughly classified into two groups according to the type of accentuation. A set of rules was constructed for generating fundamental frequency contours of complex sentences of Japanese from linguistic information. Perceptual tests of naturalness of intonation using synthetic speech with rule-generated fundamental frequency contours indicated the validity of the rules.

Abnormal noise detector for use in the inspection of gear units

Abstract: An abnormal noise detector for detecting abnormal noises resulting from a marred tooth surface in a gear of a gear unit is disclosed. A first embodiment of a detector comprises a microphone placed in the vicinity of a gear unit to be tested, a bandpass filter for filtering the output of the microphone so as to pass only an integral multiple of the fundamental frequency of noise due to meshing of the gears of the gear unit, a rectifier for rectifying the filtered output from the bandpass filter, a differentiator for differentiating with respect to time the DC output from the rectifier, a waveform shaper for shaping the output from the differentiator into pulses suitable for counting, and a pulse counter for quantifying the pulses in the output from the waveform shaper. A second embodiment comprises a microphone, a digital frequency analyzer, and a data monitoring computer responsive to the digital frequency analyzer for monitoring the output thereof.

Space-phasors for dynamic minimum-time computing and digital real-time three-phase display

Abstract: Dynamic-state calculations of power systems are generally performed with original RST-components The number of the nodes and branches can be reduced in the case of cyclic symmetry of the equipment by application of modal components Most adventageous are Space-Phasor components, because they need the least number of nodes and branches and are time-independent constant in stationary-state Differential equations can be described shortly by operators For integration a special method with factorized Eigenvalues is developed, which is necessary for the back-transformation As a result of the exact synchronization reached hereby, all admittances become real; only the source-currents in the nodes are complex outside of the homopolar components In places, where unsymmetrical faults occur or equipment with nonlinear characteristic is installed, the Space-Phasor components are coupled A digital real-time interface for transformation of original RST-quantities to Space-Phasor components was developed, which enables to measure the momentary frequency of the rotating field as well An attached calculator performes the high sensitive measurement of the desired symmetrical and harmonic component, eg the negative-sequence voltage component on fundamental frequency or any desired harmonic as term of the positiv-, negativ- und zero-sequence component

Discrimination of fundamental frequency of synthesized vowel sounds in a noise background.

Abstract: An experiment was carried out, investigating the relationship between the just noticeable difference of fundamental frequency (jndf0) of three stationary synthesized vowel sounds in noise and the signal‐to‐noise ratio. To this end the S/N ratios were measured at which listeners could just discriminate a series of changes in f0 in the range from 10% to 0.5%. Similar measurements were obtained for pulse trains and for pure tones as a reference for the results. A measure of S/N ratio based on an approximation of the critical bandwidth appeared to provide a fairly good predictor of the masked threshold of each signal, measured in a second experiment. Using this measure, it was found that a given change in the fundamental of a pulse train could be discriminated at a lower S/N ratio than in a pure tone with a frequency equal to that fundamental. The results for the vowel sounds were found to be in between those for a low‐frequency pure tone and those for a pulse train. Owing to the signal‐generation method (viz., changing f0 by changing the sampling frequency), three cues could in principle be used to discriminate a change in the fundamental of a vowel: A change in the residue pitch, a change in the pitch of a single prominent harmonic, or a change in the spectral envelope of the signal. It can be inferred from the results that the subjects used that particular cue which yielded best performance. Which cue was optimal depended not only on the vowel but also on f0 and on the presented change in f0. It seems, however, that the pitch of a single harmonic was the cue most often used. Another interesting result is that changes in f0 greater than about 5%, could for each signal be discriminated when the signal was just above masked threshold.

Digital pulse width modulation motor control system

Abstract: An adjustable frequency AC motor drive control system includes pulse width modulation control of an inverter coupled with the motor and a programmed microprocessor which generates a cosine wave in cooperation with a sine wave and a carrier wave to provide a synthesized sine wave voltage to the motor by controlling the conduction of power switches at a rate higher than the fundamental frequency of the sine wave voltage output.

Simultaneous Measurements of Mean Air Flow Rate, Fundamental Frequency and Voice Intensity

Abstract: 楽な発声における平均呼気流率 (U) , 声の基本周波数 (Fo) , 声の強さ (I) についての正常域を得るためには, 異なる性と種々の年齢群の膨大な数の対象について調べなければならない.これは1人の研究者, 1つの施設では容易な仕事ではない.この論文の目的は, (1) 限られた数の対象から得られた成績を報告すること, (2) 統計処理の例を示すこと, (3) われわれのデータを利用したいほかの研究者のために記録にとどめおくこと, にある.各パラメータの分布パタンは幹-葉表示, 箱-ひげグラフ, mids, 25%pseudspreadを用いて検討した.はずれ値はSmirnoffの検定を用いて検出した.UとFoについては, 対数変換と平方根変換を試みた.Uの平均値と棄却限界は男で156cm3/secと99～246cm3/sec, 女で158cm3/secと96～260cm3/secであった.Foの平均値と棄却限界は男で121Hzと85～164Hz, 女で238Hzと205Hzであった.Iの平均値と棄却限界は男で75dBと60～84dB, 女で69dBと62～77dBであった.

Frequency source having YIG absorption/transmission filter

Abstract: An electronically tunable solid-state microwave frequency source comprises a transmission-absorption filter incorporated within a magnetic structure. The transmission-absorption filter is employed with a tunable solid-state oscillator and tunable solid-state multiplier to provide a continuously tunable microwave signal source with enhanced spurious signal attenuation over a multiple-octave tuning range. The filter structure comprises a sphere of monocrystalline garnet such as yttrium iron garnet (YIG) and two coupling loops disposed in the field region of an adjustable field DC magnet. The coupling loops are disposed orthogonal to the magnetic field and to each other. In a specific embodiment the first coupling loop is operative to receive at its input the fundamental frequency signal and at its output is grounded, and the second coupling loop is operative to receive a harmonic input signal at its input and to convey a desired output signal at its output. The magnetic sphere of the transmission-absorption filter typically shares the magnetic field of the YIG sphere used to produce the output of the tuned oscillator. The transmission-absorption filter is incorporated into a source including a switch, a fundamental frequency amplifier and a harmonic frequency amplifier.

Dynamic characteristics of a space-station solar wing array

Abstract: A solar-wing-array concept is described which meets space-station requirements for minimum fundamental frequency (0.4 Hz), component modularity, and growth potential. The basic wing-array design parameters are varied, and the resulting effects on the array vibration frequencies and mode shapes are assessed. The transient response of a free-free space station (incorporating a solar-wing-array point design) to a load applied at the space-station center is studied. The use of the transient response studies in identifying critically loaded structural members is briefly discussed. The final 150-kW space-station configuration has a fundamental elastic frequency of 0.403 Hz.