Overtone singing: productive mechanisms and acoustic data.

Overtone singing is where one person sings in two voices, the first voice represented by the fundamental and the second by an enhanced harmonic. Overtone singing is performed in chest register. Tuning of the first or second formant and a reduction of the formant bandwidth down to 20 Hz make harmonics prominent. Narrowing the pharynx, velar constriction, variation of the small mouth opening, and a tension of the walls of the mouth cavity are used. Changing prominent harmonics has the effect of creating an overtone melody with sustained tones, tone steps, and trillos.

Quantitative evaluation of phonetograms in the case of functional dysphonia.

According to the laryngeal clinical findings, figures making up a scale were assigned to vocally trained and vocally untrained persons suffering from different types of functional dysphonia. The different types of dysphonia--from the manifested hypofunctional to the extreme hyperfunctional dysphonia--were classified by means of this scale. Besides, the subjects' phonetograms were measured and approximated by three ellipses, what rendered possible the definition of phonetogram parameters. The combining of selected phonetogram parameters to linear combinations served the purpose of a phonetographic evaluation. The linear combinations were to bring phonetographic and clinical evaluations into correspondence as accurately as possible. It was necessary to use different kinds of linear combinations for male and female singers and nonsingers. As a result of the reclassification of 71 and the new classification of 89 patients, it was possible to graduate the types of functional dysphonia by means of computer-aided phonetogram evaluation with a clinically acceptable error rate. This method proved to be an important supplement to the conventional diagnostics of functional dysphonia.

Influence of unilateral vocal fold fixation on the structure of the intrinsic laryngeal muscles.

Histomorphometric data (fiber frequencies, fiber diameters, and atrophy factors) were determined in laryngeal muscles [thyroarytenoid (VOC), posterior (PCA) and lateral (LCA) cricoarytenoids, and cricothyroid (CT) muscles]. Seventy-three muscles (43,700 fibers) from normal and carcinoma-infiltrated sides of the larynges of 11 patients were analyzed. The fiber diameters showed uniform values of 24.2 +/- 9.1 microns. Type-I fibers were more frequent in the PCA and less frequent in the LCA and the CT. In the VOC, the ratio was 1:1. The unilateral fixation of a vocal fold modified the structures of the LCA and the CT. The VOC and the PCA were not affected. A hypothesis based on the phonatory function of the CT is used to explain its atrophy.

[What is the value of measuring "singer's formant" in phoniatry?]. / Welchen Wert hat die Messung des "Sängerformanten" in der Phoniatrie?

The singing formant is the product of an articulatory gesture. Devices for phonetogram measurement often claim the ability to determine it. However, they measure rather the overtone content or the noise of the voice than the formant. Moreover, the voice efficiency (ratio of the sound pressure in the frequency band 2-5 kHz to the total sound pressure), also measured by these devices, is not defined in a physical or physiological sense. Such measurement does not evaluate the efficiency of the vocal apparatus.

[Assessing the quality of the speaking voice after therapy of T1 and T2 vocal cord cancers]. / Die Bestimmung der Qualität der Sprechstimme nach Therapie von T1- und T2-Stimmlippenkarzinomen.

All studies which analysed voice quality after T1 and T2 glottic cancer employed sustained vowels for evaluation. Sustained vowels can often be produced more clearly than expected in a severe degree of hoarseness in running speech. In this investigation voice quality was analysed by measuring the signal-to-noise-ratio (SNRc) in running speech. For evaluation these data were correlated to the scores from an auditive evaluation and from a clinical examination of the larynx considering functional parameters. 39 patients were examined after different therapies (primary radiation, chordectomy, frontolateral partial resection). The grading of the three different methods for characterisation of the voice quality correlated well. Therefore the SNRc is presumed to be a valuable additional method to the psychoacoustic voice evaluation. Comparison of voice quality after different therapies provided no significant difference between radiotherapy and chordectomy. The functional results after frontolateral partial resection were significantly less satisfying as expected.

Computer aided evaluation of phonetograms.

The phonetogram represents an area limited by piano and forte contours of the sound pressure levels along the vocal range. Phonetograms are used in the diagnosis of voice status. Apart from reference phonetograms and the extraction of single parameters, phonetograms have not been evaluated quantitatively in medical practice. The present computer program divided the phonetogram into subareas which were approximated by simple patterns (ellipses). The ellipse parameters were used to evaluate voice efficiency, to recognize voice categories, and to derive diagnostic comments.

[Computer-assisted phonetography as a diagnostic aid in functional dysphonia]. / Computergestützte Stimmfeldauswertung als Diagnostikhilfe bei funktionellen Dysphonien.

A total of 160 voice-trained and untrained subjects with functional dysphonia were given a "clinical rating" according to their clinical findings. This was a certain value on a scale that recorded the degree of functional voice disorder ranging from a marked hypofunction to an extreme hyperfunction. The phonetograms of these patients were approximated by ellipses, whereby the definition and quantitative recording of several phonetogram parameters were rendered possible. By means of a linear combination of phonetogram parameters, a "calculated assessment" was obtained for each patient that was expected to tally with the "clinical rating". This paper demonstrates that a graduation of the dysphonic clinical picture with regard to the presence of hypofunctional or hyperfunctional components is possible via computerised phonetogram evaluation. In this case, the "calculated assessments" for both male and female singers and non-singers must be computed using different linear combinations. The method can be introduced as a supplementary diagnostic procedure in the diagnosis of functional dysphonia.

[In vivo nuclear magnetic resonance tomography measurement of vocal cord temperature during phonation]. / Kernspintomographische In-vivo-Messung der Stimmlippentemperatur während der Phonation.

In the glottal area, a series of transversal sections was recorded by means of a nuclear magnetic resonance tomograph using the technique of fast FLASH recording. During the record, the subject uttered the vowel [a:] with 180 Hz and 80 dB(A). The flip angle (35 degrees C) was chosen so as to get maximum contrast in the tissue tomogram due to a temperature shift. The tissue temperature was evaluated by the measurement of the dependence of the relaxation time on the temperature in a gelatinized and doped test solution which was similar in relaxation times to the tissue. In the vocal folds, the temperature increased by about 4 degrees C after prolonged phonation (20 x 20 s). The importance of this technique and the result is discussed with reference to the phonatory function of the larynx.

[The voice of the singer in the phonetogram]. / Die Stimme des Sängers im Phonetogramm.

Phonetograms were subdivided into areas approximating voice registers. By means of an analytical description of the areas, parameters could be established for a differentiation of voice categories and efficiency. The evaluation of 21 untrained and 34 trained voices showed a significant difference between the two groups. Male singers demonstrated more efficiency in the head and chest registers than male non-singers; female singers showed a stronger efficiency only in the head voice in comparison with their non-singer counterparts. Proceeding from voice sound alone, voices are often misclassified regarding the voice categories, and voice problems arise. Moreover, enhanced training of only chest or head voice function results in functional disorders in the singing voice. Such cases can be demonstrated by means of phonetograms.

Recognition of low-level alcohol intoxication from speech signal.

Eleven male subjects were required to read a text in both sober and alcohol intoxicated conditions. By means of statistical signal analysis, frequency distributions of fundamental frequency (F0), signal-to-noise ratio (SNR), ratio of first- to second-formant frequencies (F1/F2), variation speed of the frequencies F0, F1, F2, and the long-term average spectrum (LTAS) were determined. The distributions were examined for their suitability in discriminating between sober and intoxicated conditions. The SNR and F0 distributions as well as the LTAS discriminated with an error rate less than 5%. Combination of SNR and F0 profiles enabled correct discrimination in all cases. The parameter F1/F2 describing the articulation varied strongly among individuals. It was modified only with high levels of blood alcohol. Frequency variation speeds were not altered by intoxication. Speaker recognition by means of LTAS was interpreted as a perturbation of laryngeal movement control, where long-term voice effort was found to produce similar effects to alcohol intoxication. On the basis of the present results and various other factors (ambiguity of the sources of the acoustic effects, expense of the procedure), application of acoustic analysis in forensic medicine for recognition of low-level alcohol intoxication is considered inexpedient.

[Hoarseness]. / Das Heiserkeitsfeld.

By means of measuring fundamental frequency, amplitude and voice quality (signal-to-noise ratio) of voiced signal segments in speech, a three-dimensional representation was established. The record of voice quality versus pitch and intensity overcomes all the disadvantages which are met within the voice field (sustained vowels, extreme voice sound pressures, missing quality information etc.).

[The 3-dimensional voice field]. / Das dreidimensionale stimmfeld.

Extension of the voice field (voice profile) by a third variable which characterizes the phonation has various advantages as well as drawbacks. Since the voice field evaluates the laryngeal function, the use of aerodynamic variables improve the representation of the laryngeal efficiency in the voice field. On the other hand, the measurement of these variables complicates the method. When voice quality measures (presence of singing formant, sharpness) are used as the third dimension, the limits of the voice field are unique references for the measures. However, the voice quality at the physiologic limits is not representative of the voice as produced in singing or speaking. Measures which characterize the "hoarseness" of the voice yield important results with respect to the perturbation of the voice production (jitter, shimmer, additive noise). The perturbation measures evaluate the laryngeal function at defined points in the frequency--intensity area. However, in forte phonation, the natural perturbation is reduced, in piano phonation, the perturbation is increased, and the results cannot be interpreted in relation to the perturbation magnitude within the voice field. Besides, the measurement of perturbation requires digital signal processing. If EMG data are used for the voice field, as it is shown for the M. vocalis, the voice field reveals interesting relationships between acoustic and physiologic features. For instance, in the piano phonation, the EMG signal power is constant on a low level. In the forte phonation, in the chest register, the EMG signal power shows a medium level and a high level in the head register. In the falsetto, however, the EMG signal power is low.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative spectral evaluation of shimmer and jitter.

A vowel [a]-like, synthesized speech wave was perturbated by defined and comparable jitter and shimmer levels. The signal-to-noise ratio was calculated from the speech wave spectra. Noise emerges in those spectral regions in which the harmonics have high amplitudes, that is, at low frequencies and in the formant regions. Jitter created noise levels significantly higher than shimmer. To verify the theoretical findings, the voices of 32 women with functional voice disorders were analyzed for shimmer and jitter. It was found that only jitter is relevant for differentiating between hypo- and hyperfunctional voice disorders. Jitter was reduced in hyperfunctional voice disorder. This is presumed to be an effect of the high vocal fold tension found in the disorder.

[Evaluation of the voice as a secondary sex characteristic in transsexuals]. / Die Bewertung der Stimme als sekundäres Geschlechtsmerkmal bei Transsexuellen.

The secondary sex character of the voice was assessed in 15 transsexuals. They were compared to 40 people with typical normal vocal sex characteristics. The mean pitch level and the distributions of formant frequencies of the transsexuals were compared to those of the control group. The results obtained show no significant relation to the phenotype.

[The activity of the supraglottal sphincter during phonation]. / Die Aktivität des supraglottalen Sphinkters bei der Phonation.

By means of the measurement of the aperture of the upper laryngeal sphincter it is shown that the sphincter constriction increases when the pitch is lowered and/or the voice intensity is raised. The sphincter movement does not result from the action of extrinsic laryngeal muscles. Moreover, the action of the adductor muscles results in a constriction of the supraglottal sphincter. Out of this group of muscles the lateral thyroarytenoid muscle is dominant. Since it is the strongest muscle of the group of adductors, it also activates the glottal and the supraglottal sphincters, and only this muscle guarantees glottal closure at a relaxed vocalis muscle (low pitch) and/or high subglottal pressure (high intensity). EMG data acquired from the lateral thyroarytenoid muscle at phonation at various pitch levels and different voice intensities confirm the assumed muscular function. The EMG activity increases with descending pitch level and/or with increasing voice intensity.

[The role of the cricopharyngeal muscle in phonation]. / Die Rolle des Musculus cricopharyngeus bei der Phonation.

Intraluminal esophageal manometry has been employed to study cricopharyngeal muscular function at different pitch levels. The activity of the cricopharyngeal muscle (CP) increases continually with rising pitch but is not influenced by the vocal sound pressure level. In the lower part of the chest register, the muscular pressure is lower than the pharyngo-esophageal pressure at rest. At high pitch levels, the pressure is higher than during swallowing. The CP has a dual function: With increasing pitch, the CP cooperates synergistically with the cricothyroid muscle (CT), indicated by increasing muscular pressure in the upper esophageal sphincter. On the other hand, the CP shortens the vocal cords by rotating the cricoid cartilage in anterior direction, thus acting antagonistically to the CT.