Measures Of Fundamental Frequency Research Articles

Ambulatory Monitoring of Disordered Voices

Recently developed systems for ambulatory monitoring of voice use employ miniature accelerometers placed at the base of the anterior neck to sense phonation. As it is hoped that such systems will help improve the clinical assessment and management of voice disorders, this study was undertaken to determine the impact of dysphonia severity on the accuracy of accelerometer-based estimates of vocal function. Simultaneous recordings were made of oral acoustic (microphone) and neck skin acceleration signals for 6 normal speakers and 18 patients with voice disorders (mild to severe dysphonia) as they performed several speech tasks. Measures of phonation time, fundamental frequency, and sound pressure level were extracted from the two types of signals and compared. It was generally demonstrated that accelerometer-based measures closely approximated corresponding measurements obtained from a microphone signal across all levels of dysphonia severity. Furthermore, there was evidence that in some cases the accelerometer may actually represent a more robust approach for estimating phonation parameters in disordered voices. The results generally support the recent application of accelerometers as phonation sensors in ambulatory voice monitoring systems that can be used in the clinical assessment and management of voice disorders.

Standardization of acoustic measures for normal voice patterns

SummaryStudies have established that normative data is necessary for acoustic analysis. The aim of the present study is to standardize fundamental frequency measures (fo), jitter, shimmer and harmonic-noise ratio (HNR) for young adults with normal voice.Method20 males and 20 females, between 20 and 45 years, without signs and symptoms of vocal problems; CSL-4300 Kay-Elemetrics; vowels /a/ and /é/.Resultsfor females, vowels /a/ and /é/ had average measures of: fo 205.82 Hz and 206.56 Hz; jitter of 0.62% and 0.59%; shimmer of 0.22 dB and 0.19 dB; PHR of 10.9 dB and 11.04 dB, respectively. For males, vowel /a/ and /é/ had average measures of: fo 119.84 Hz and 118.92 Hz; jitter of 0.49% and 0.5%; shimmer of 0.22 dB and 0.21 dB; HNR 9.56 dB and 9.63 dB, respectively. Both fo and NHR female measures were significantly higher than their male counterparts.Conclusionour results differ from the literature; therefore, it is important to standardize the program in use.

Fundamental wave extraction and frequency measurement based on IIR wavelet filter banks

A wavelet function with good frequency response was adopted and the optimal decomposition level of wavelet transform was studied in order to improve the accuracy of fundamental wave extraction and frequency measurement in signal processing. In frequency measurements, an evaluating method was proposed to determine right maximal value points, and the fundamental frequency of signal was estimated by the least squares method, which could reduce the influence of low frequency noises. An interpolation method in parabola form was used to eliminate the error of the non-integral period sampling. A digital signal processing system was developed with a digital signal processor (DSP) to realise the wavelet filter and frequency measurement algorithms in real time. The testing results show that both the methods and system proposed by this paper are effective.

Padrões acústicos da voz em indivíduos com a doença vibroacústica

Background: Long-term low frequency noise exposure (LFN) (≤ 500Hz, including infrasound) may lead to the development of vibroacoustic disease (VAD), a systemic pathology characterized by the abnormal growth of extra-cellular matrices. The respiratory system is a target for LFN. Fibrosis of the respiratory tract epithelia was observed in VAD patients through biopsy, and confirmed in animal models exposed to LFN. Voice acoustic analysis can detect vocal fold variations of mass, tension, muscular and neural activity. Frequency perturbation (jitter), amplitude perturbation (shimmer) and harmonic-to-noise ratio (HNR) are used in the evaluation of the vocal function, and can be indicators of the presence and degree of severity of vocal pathology. Since the respiratory system is the energy source of the phonation process, this raises questions about the effects of VAD on voice production. The purpose of this study was to determine if voice acoustic parameters of VAD patients are different from normative data. Methods: Nine individuals (5 males and 4 females) diagnosed with VAD were recorded performing spoken and sung tasks. The spoken tasks included sustaining vowels and fricatives. The sung tasks consisted of maximum phonational frequency range (MPFR). Voice acoustic parameters analysed were: fundamental frequency (F0), jitter, shimmer, HNR and temporal measures. Results: Compared with normative data, both males and females diagnosed with VAD exhibited increased F0, shimmer and HNR. Jitter, MPFR and one temporal measure were reduced. Conclusions: VAD individuals presented voice acoustic parameter differences in spectral, temporal and perturbation measures, which may be indicative of small morphological changes in the phonatory system.Rev Port Pneumol 2006; XII (4): 375-382

Voice acoustic patterns of patients diagnosed with vibroacoustic disease

BackgroundLong-term low frequency noise exposure (LFN) (≤500Hz, including infrasound) may lead to the development of vibroacoustic disease (VAD), a systemic pathology characterized by the abnormal growth of extra-cellular matrices. The respiratory system is a target for LFN. Fibrosis of the respiratory tract epithelia was observed in VAD patients through biopsy, and confirmed in animal models exposed to LFN. Voice acoustic analysis can detect vocal fold variations of mass, tension, muscular and neural activity. Frequency perturbation (jitter), amplitude perturbation (shimmer) and harmonicto- noise ratio (HNR) are used in the evaluation of the vocal function, and can be indicators of the presence and degree of severity of vocal pathology. Since the respiratory system is the energy source of the phonation process, this raises questions about the effects of VAD on voice production. The purpose of this study was to determine if voice acoustic parameters of VAD patients are different from normative data. MethodsNine individuals (5 males and 4 females) diagnosed with VAD were recorded performing spoken and sung tasks. The spoken tasks included sustaining vowels and fricatives. The sung tasks consisted of maximum phonational frequency range (MPFR). Voice acoustic parameters analysed were: fundamental frequency (F0), jitter, shimmer, HNR and temporal measures. ResultsCompared with normative data, both males and females diagnosed with VAD exhibited increased F0, shimmer and HNR. Jitter, MPFR and one temporal measure were reduced. ConclusionsVAD individuals presented voice acoustic parameter differences in spectral, temporal and perturbation measures, which may be indicative of small morphological changes in the phonatory system.

On the internal frost resistance of self-compacting concrete, with and without polypropylene fibres

In this article experimental and numerical studies of internal frost resistance of self-compacting and normal concrete, with and without fibres, are outlined. For this purpose self-compacting concrete with low water-cement ratio was studied, with varying amounts of filler, crystalline or sedimentary, different pouring pressures and different mixing procedure with two ages at the start of testing. The concrete was frozen twice a day at ±20°C all around the specimen up to 300 cycles. Measurement of length, weight and internal fundamental frequency were performed at the start of testing, at 100 cycles and at 300 frost cycles. Tests were also carried out on submerged cast self-compacting concrete and on self-compacting concrete with fibres. In reference tests normal concrete was studied in parallel. In general self-compacting concrete behaved well or better than normal concrete to internal frost except for the submerged cast concrete, where large segregation occurred and low internal frost resistance followed. The main reasons for low internal frost resistance in submerged applications were probably differences in water-cement ratio in the casting due to cement, water or/and aggregate segregation. Polypropylene fibres in concrete seemed to prohibit the movement of water in the air void system so that a sudden internal collapse occurred before 300 frost cycles. (Less)

The interaction of linguistic and affective prosody in a tone language

To address how a common set of acoustic properties of speech prosody modulate to convey linguistic and affective meanings concurrently, this study investigated the influence of phonemic tones on the expression of emotion (happy, sad, angry) and linguistic modality (declarative, interrogative) in a tone language, Punjabi. Base stimuli consisted of neutral sentences with either of the three contrastive tones in Punjabi (falling, level, high-rising) varying at the object position of the sentence only. Each of these sentences was elicited as a statement or a question for each of the three emotions by 6 native Punjabi speakers. Utterances were validated for adequate representation of the target emotion, and reliable exemplars for each of the emotions and linguistic modality were subjected to detailed acoustic analysis. Fundamental frequency and duration measures were analyzed for the stressed vowel of the keywords (subject, object, verb) and the whole utterance for each of the tokens. Results demonstrated ways that the acoustic correlates of tone at the word level interact with that of the intonation and emotion at the sentence level, which were further compared with previous results on the effect of focus on intonation and emotional prosody [M. D. Pell, J. Acoust. Soc. Am. 109, 1668–1680 (2001)].

Multidimensional analyses of voicing offsets and onsets in female speakers

This study investigates cross-speaker differences in the factors that predict voicing thresholds during abduction-adduction gestures in six normal women. Measures of baseline airflow, pulse amplitude, subglottal pressure, and fundamental frequency were made at voicing offset and onset during intervocalic /h/, produced in varying vowel environments and at different loudness levels, and subjected to relational analyses to determine which factors were most strongly related to the timing of voicing cessation or initiation. The data indicate that (a) all speakers showed differences between voicing offsets and onsets, but the degree of this effect varied across speakers; (b) loudness and vowel environment have speaker-specific effects on the likelihood of devoicing during /h/; and (c) baseline flow measures significantly predicted times of voicing offset and onset in all participants, but other variables contributing to voice timing differed across speakers. Overall, the results suggest that individual speakers have unique methods of achieving phonatory goals during running speech. These data contribute to the literature on individual differences in laryngeal function, and serve as a means of evaluating how well laryngeal models can reproduce the range of voicing behavior used by speakers during running speech tasks.

Predicting fundamental frequency from mel-frequency cepstral coefficients to enable speech reconstruction

This work proposes a method to reconstruct an acoustic speech signal solely from a stream of mel-frequency cepstral coefficients (MFCCs) as may be encountered in a distributed speech recognition (DSR) system. Previous methods for speech reconstruction have required, in addition to the MFCC vectors, fundamental frequency and voicing components. In this work the voicing classification and fundamental frequency are predicted from the MFCC vectors themselves using two maximum a posteriori (MAP) methods. The first method enables fundamental frequency prediction by modeling the joint density of MFCCs and fundamental frequency using a single Gaussian mixture model (GMM). The second scheme uses a set of hidden Markov models (HMMs) to link together a set of state-dependent GMMs, which enables a more localized modeling of the joint density of MFCCs and fundamental frequency. Experimental results on speaker-independent male and female speech show that accurate voicing classification and fundamental frequency prediction is attained when compared to hand-corrected reference fundamental frequency measurements. The use of the predicted fundamental frequency and voicing for speech reconstruction is shown to give very similar speech quality to that obtained using the reference fundamental frequency and voicing.

Fundamental Frequency Histograms Measured by Electroglottography During Speech: A Pilot Study for Standardization

This study was designed to develop a database for the electroglottographic measurement of fundamental frequency (Fo) in normal subjects in running speech, for reference in the diagnosis and follow-up of dysphonic patients. A prospective pilot study included 20 healthy male volunteers without laryngeal disorder. Electroglottographic recordings of speaking Fo during connected speech (French) were obtained from two texts with different prosodic content. Fo histograms were sensitive to the variation of speaking Fo between both texts. Graphic representation of the range and distribution of the Fo of the speaker were designed as normalized Fo histograms with plot lines at 5th and 95th percentiles. Less than 5% variability of Fo histograms was recorded when recording more than 15 subjects. This pilot study designed a graphic display of standardized electroglottographic Fo measurements during the physiological condition of connected speech. As the degree of Fo variability depends on the phonetic contents of the text and on the language spoken, a separate histogram for normal subjects needs to be developed in each country or at least for each voice laboratory, with a standard, previously chosen text.

Influence of sampling rate on accuracy and reliability of acoustic voice analysis

It is universally recognized that sampling rate (FS) influences the reliability and validity of acoustic voice measurements; however, an exact relationship has not been determined. The purpose of this experiment was to investigate the influence of FS on acoustic voice quality measurements, while considering the influences of gender, intra-subject variability, microphone, environmental noise, data acquisition hardware, and analysis software as balancing factors. The impact of FS, from 44.1 kHz to 10 kHz, was explored by analyzing 864 000 measures of fundamental frequency, jitter, and shimmer, using three software analysis systems: MDVP, TF32, and PRAAT. Results suggest that the recommended, acceptable, and critical FS for acoustic voice analysis are above 26 kHz, above 19 kHz, and 12 kHz, respectively. Thus, voice samples captured above 26 kHz can be used for data analysis and compared without introducing error due to FS.

Influence of Data Acquisition Environment on Accuracy of Acoustic Voice Quality Measurements

Accuracy of acoustic voice analysis is influenced by the quality of recording. Lately, articles have suggested that soundcards perform equivalently to specialized professional-grade data acquisition (DA) systems. The purpose of this study was to investigate the influence of DA environment (DA system and microphone) on acoustic voice quality measurement (VQM) while balancing for gender, age, intersubject and intrasubject variability, and analysis software. More specifically, the relative performance of different hardware environments and the relationship between their technical characteristics and VQM performance was investigated. The discretization error and the effective dynamic range of the different DA environments were measured. We used 3 software systems to record and measure separately 2000 acoustic samples of sustained phonation for fundamental frequency, jitter, and shimmer. Analyses of variance (ANOVA) were performed with these parameters as the dependent variables. The results of the study suggested that professional-grade DA hardware is strongly recommended to provide accurate and valid voice assessment. The fundamental frequency measurement differences across DA environments were highly correlated to the discretization error (r=1.00), whereas jitter and shimmer were highly correlated to the effective dynamic range of the DA environments (r=-0.68 and r=-0.86, respectively).

Acoustic-phonetic correlates of talker intelligibility for adults and children

This study investigated acoustic-phonetic correlates of intelligibility for adult and child talkers, and whether the relative intelligibility of different talkers was dependent on listener characteristics. In experiment 1, word intelligibility was measured for 45 talkers (18 women, 15 men, 6 boys, 6 girls) from a homogeneous accent group. The material consisted of 124 words familiar to 7-year-olds that adequately covered all frequent consonant confusions; stimuli were presented to 135 adult and child listeners in low-level background noise. Seven-to-eight-year-old listeners made significantly more errors than 12-year-olds or adults, but the relative intelligibility of individual talkers was highly consistent across groups. In experiment 2, listener ratings on a number of voice dimensions were obtained for the adults talkers identified in experiment 1 as having the highest and lowest intelligibility. Intelligibility was significantly correlated with subjective dimensions reflecting articulation, voice dynamics, and general quality. Finally, in experiment 3, measures of fundamental frequency, long-term average spectrum, word duration, consonant-vowel intensity ratio, and vowel space size were obtained for all talkers. Overall, word intelligibility was significantly correlated with the total energy in the 1- to 3-kHz region and word duration; these measures predicted 61% of the variability in intelligibility. The fact that the relative intelligibility of individual talkers was remarkably consistent across listener age groups suggests that the acoustic-phonetic characteristics of a talker's utterance are the primary factor in determining talker intelligibility. Although some acoustic-phonetic correlates of intelligibility were identified, variability in the profiles of the "best" talkers suggests that high intelligibility can be achieved through a combination of different acoustic-phonetic characteristics.

Fragments of a Greek Trilogy: impact on phonation

Summary This study documents the vocal characteristics of an actor before and after a series of eight performances involving extended voice use. The hypothesis was that this type of extended voice use would result in symptoms of vocal abuse and that damage to the actor's voice would be evident in measures made after the performance series. Three pre-performance and three post-performance speech samples were gathered and analyzed using the CSL and Visipitch II. Measurements taken included maximum phonational range; maximum sustained phonation; fundamental frequency during reading; maximum intensity levels; sound pressure levels for soft, moderate, and loud productions of sustained /a/; and perturbation including jitter, shimmer, harmonics-to-noise ratio, and an s/z ratio. Pre- and post-performance samples of the “Rainbow passage” and sustained vowel phonation were rated by a group of blinded listeners that included professional voice trainers and speech pathologists. In addition, sample lines from the performance were played for the listeners to judge whether this technique would result in symptoms of vocal abuse. Eleven out of 12 professional voice trainers rated that this technique would result in symptoms of vocal abuse. The data revealed post-performance improvement in phonational range, maximum intensity levels, perturbation measures, and s/z ratio. Measures of maximum sustained phonation, fundamental frequency, and sound pressure levels remained stable. Videoendoscopy revealed normal function of the larynx and vocal folds.

A novel method for fundamental frequency measurement of multi-harmonic signals with noises using numerical differentiation

A high-accuracy, wide-range frequency estimation algorithm for the non-sinusoidal signals with white Gaussian noises basing on a numerical differentiation and central Lagrange interpolation is proposed in this paper. The proposed algorithm needs 7 sample points for frequency estimation of the signals with 3 order harmonics. The sample frequency is not restricted by the real value of the frequency of the non-sinusoidal signal and the mean of the noises. Under conditions with white noise, the frequency of the signal is estimated at an error of 0.001% over 1 Hz to 1000 kHz with the amplitudes of 1st, 2nd and 3rd of the non-sinusoidal signal varying from 1 to 320 V and the phase angle of 1st, 2nd and 3rd of the non-sinusoidal signal varying from 0 to 360 in at most half cycle. Using Matlab software, the simulation results of the test example are satisfactory.

Acoustic and perceptual characteristics of vowels produced during simultaneous communication

This study investigated the acoustical and perceptual characteristics of vowels in speech produced during simultaneous communication (SC). Twelve normal hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking a set of sentences containing monosyllabic words designed for measurement of vowel duration, formant frequencies, and fundamental frequency in consonant–vowel–consonant (CVC) syllables and 60 listeners audited the speech samples. Although results indicated longer sentence and vowel durations for SC than SA, the data showed no difference in spectral characteristics of vowels produced during SC versus SA, indicating no degradation of vowel spectrum by rate alteration during SC. Further, no difference was found in listeners’ ability to identify vowels produced during SC versus SA, indicating no degradation of vowel perceptual cues during SC. These conclusions are consistent with previous research indicating that temporal alterations produced by SC do not produce degradation of segmental acoustical characteristics of spoken English. Learning outcomes As a result of this activity, the participant will be able to (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with children who are deaf; (3) describe vowel acoustics in English speech; (4) discuss methods of measuring vowel perception; (5) specify the acoustic characteristics of vowels produced during simultaneous communication; and (6) specify the ability of listeners to perceive vowels in speech produced during simultaneous communication.

Pitch-raising surgery in fourteen male-to-female transsexuals.

To evaluate the indications and results of pitch-raising surgery in male-to-female transsexual patients. Retrospective study of male-to-female transsexual patients who underwent pitch-raising surgery between 1994 and 2001 at a single institution. The 14 patients had inadequate improvements after speech therapy alone. After anterior commissure advancement (n = 2), cricothyroid approximation (n = 9), or both (n = 3), results were evaluated subjectively by the patients and speech therapists and objectively by electroglottographic measurement of fundamental frequencies (usual, maximal, and minimal), postoperative gain in usual fundamental frequency, and the percentage of irregularities. Cricothyropexy disruption occurred in two patients. Median follow-up was 6.5 months. Subjective success rates were 78.5% and 71.5% according to the patients and speech therapists, respectively. Usual, maximal, and minimal frequencies increased significantly; median postoperative gain in usual fundamental frequency was 11 Hz. Three of the four patients with a poor objective result continued to smoke after surgery. Pitch-raising surgery induces subjective and objective improvements but should be reserved for patients in whom speech therapy is not sufficiently effective.

The self-to-other ratio applied as a phonation detector for voice accumulation

A new method for phonation detection is presented. The method utilises two microphones attached near the subject's ears. Simplified, phonation is assumed to occur when the signals appear mainly in-phase and at equal amplitude. Several signal processing steps are added in order to improve the phonation detection, and finally the original signal is sorted in separate channels corresponding to the phonated and non-phonated instances. The method is tested in a laboratory setting to demonstrate the need for some of the stages of the signal processing and to examine the processing speed. The resulting sound file allows for measurement of phonation time, speaking time and fundamental frequency of the subject and sound pressure level of the subject's voice and the environmental sounds separately. The present implementation gives great freedom for adjustment of analysis parameters, since the microphone signals are recorded on DAT tape and the processing is performed off-line on a PC. In future versions, a voice accumulator based on this principle could be designed in order to shorten analysis time and thus make the method more appropriate for clinical use.

453 咽頭内呼気流速変動による声帯振動基本周波数の測定

453 咽頭内呼気流速変動による声帯振動基本周波数の測定

Acoustic profiles of negative emotion

A study was initiated to acoustically characterize and differentiate discrete categories of negatively valenced emotions conveyed through speech prosody. Utterances elicited from eight encoders (actors) in different emotional tones were perceptually rated by a group of decoders to gauge how strongly each token was associated with the basic emotions of ‘‘anger,’’ ‘‘disgust,’’ and ‘‘sadness’’ using a seven-choice response paradigm. Tokens rated as highly representative of each target emotion by greater than 80% of decoders were examined acoustically. Measures of fundamental frequency (mean, range, sd), amplitude (mean, range, sd), and duration (speech rate, %voiced) were obtained from each token and for utterances spoken in a ‘‘neutral’’ tone by the same encoders. Normalized measures were compared among emotional categories to uncover reliable acoustic dimensions that may have contributed to perceptually distinct vocal symbols of negative emotion states. Results pointed to important differences in duration, amplitude, and especially fundamental frequency in discriminating among prosodic signals representing distinct negative emotions. These findings extend work on the acoustic underpinnings of positive and negative vocalizations in speech [M. D. Pell, J. Acoust. Soc. Am. 109, 1668–1680 (2001)], providing finer specification of these parameters within the family of ‘‘negative’’ emotions. [Work supported by NSERC.]