Biomedical subjects

J Kreiman

Publications and source records attributed to J Kreiman.

At least 37 records · Page 2Linked to original sources

PubMed1994

Effects of RLN and SLN stimulation on glottal area.

In vivo canine experiments have demonstrated that vocal fold stiffness varies proportionately with changing levels of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) stimulation. This study evaluated the morphologic changes in the glottis at varying levels of nerve stimulation and the presumed effects on laryngeal air particle velocity. Stroboscopic data from the in vivo canine model of phonation were examined under varying conditions of RLN and SLN stimulation. Computerized analysis of stroboscopic images was used to reconstruct the glottal area vs. time waveforms. As RLN stimulation increased, glottal area per cycle decreased (p < 0.05). However, as SLN stimulation increased, glottal area per cycle increased (p < 0.05). However, as SLN stimulation increased, glottal area per cycle increased (p < 0.05). These results support the hypothesis that increasing RLN stimulation at similar levels of SLN stimulation produces an increase in air particle velocity, whereas an increase in SLN stimulation causes a decrease in air particle velocity.

Airway Resistance↗

PubMed1994

A pressure-regulated model of normal and pathologic phonation.

Recent evidence suggests that the lung-thorax system functions as a constant pressure source during phonation. However, previous animal models used a constant flow source. This article describes an in vivo canine model that maintains a constant subglottic pressure during phonation to more closely simulate the pulmonary system. At any given subglottic pressure, increasing levels of recurrent laryngeal nerve stimulation resulted in a significant rise in resistance followed by a plateau. Increasing levels of superior laryngeal nerve stimulation, however, produced no significant change in glottal resistance. Three experimental conditions were studied: normal, unilateral recurrent laryngeal nerve paralysis, and paralysis followed by arytenoid adduction. In normal canines, maximal vocal efficiency values were the highest, indicating the best match between pressure and resistance. The vocal efficiency values were significantly lower in recurrent laryngeal nerve paralysis, indicating pressure-resistance mis-match. Arytenoid adduction increased the maximal vocal efficiency values and decreased the mismatch observed in the paralyzed state. These findings may provide insight into an understanding of normal and pathologic laryngeal behavior.

Airway Resistance↗

PubMed1994

Effects of arytenoid adduction on laryngeal function following ansa cervicalis nerve transfer for vocal fold paralysis in an in vivo canine model.

Laryngeal reinnervation with the ansa cervicalis has been proposed as a treatment for human unilateral vocal fold paralysis (UVFP). This study tested the assumption that results from reinnervation could be improved if combined with medialization surgery. Six canine subjects underwent recurrent laryngeal nerve section and reinnervation with a branch of the ansa cervicalis. After reinnervation, vocal function was assessed before and after arytenoid adduction. Although laryngeal function improved significantly following reinnervation, results were significantly enhanced by the addition of medialization surgery. The implications for the treatment of human unilateral vocal fold paralysis are discussed.

Animals↗

PubMed1994

Measurement of adductory force of individual laryngeal muscles in an in vivo canine model.

In this experiment, the adductory properties of three intrinsic laryngeal muscles (the thyroarytenoid [TA], lateral cricoarytenoid [LCA], and interarytenoid [IA]) were studied and quantified. Using an in vivo canine laryngeal model, a recently developed "tensionometer" was used to measure the adductory force produced by each of these muscles at the vocal process of the arytenoid. Isolated muscle activation was obtained by stimulating selective terminal branches of the anterior division of the recurrent laryngeal nerve. Results indicate that the LCA is the strongest adductory muscle, followed by the TA and the IA. Videolaryngoscopy revealed that LCA contraction causes adduction of the vocal fold and vocal process, with the predominant effect on the process. TA stimulation leads primarily to adduction of vocal fold, and the IA adducts mainly the vocal process. Implications of these findings are discussed.

Animals↗

PubMed1993

Comparing internal and external standards in voice quality judgments.

A new descriptive framework for voice quality perception (Kreiman, Gerratt, Kempster, Erman, & Berke, 1993) states that when listeners rate a voice on some quality dimension (e.g., roughness), they compare the stimulus presented to an internal standard or scale. Hypothetically, substituting explicit, external standards for these unstable internal standards should improve listener reliability. Further, the framework suggests that internal standards for vocal qualities are inherently unstable, and may be influenced by factors other than the physical signal being judged. Among these factors, context effects may cause drift in listeners' voice ratings by influencing the internal standard against which judgments are made. To test these hypotheses, we asked 12 clinicians to judge the roughness of 22 synthetic stimuli using two scales: a traditional 5-point equal appearing interval (EAI) scale and a scale with explicit anchor stimuli for each scale point. The stimulus set included a relatively large number of normal and mildly rough voices. We predicted that this would produce an increase in the perceived roughness of moderately rough stimuli over time for the EAI ratings, but not for the explicitly anchored ratings. Ratings made using the anchored scale were significantly more reliable than those gathered using the unanchored paradigm. Further, as predicted, ratings on the unanchored EAI scale drifted significantly within a listening session in the direction expected, but ratings on the anchored scale did not. These results are consistent with our framework and suggest that explicitly anchored paradigms for voice quality evaluation might improve both research and clinical practice.

Adult↗

PubMed1993

Perceptual evaluation of voice quality: review, tutorial, and a framework for future research.

The reliability of listeners' ratings of voice quality is a central issue in voice research because of the clinical primacy of such ratings and because they are the standard against which other measures are evaluated. However, an extensive literature review indicates that both intrarater and interrater reliability fluctuate greatly from study to study. Further, our own data indicate that ratings of vocal roughness vary widely across individual clinicians, with a single voice often receiving nearly the full range of possible ratings. No model or theoretical framework currently exists to explain these variations, although such a model might guide development of efficient, valid, and standardized clinical protocols for voice evaluation. We propose a theoretical framework that attributes variability in ratings to several sources (including listeners' backgrounds and biases, the task used to gather ratings, interactions between listeners and tasks, and random error). This framework may guide development of new clinical voice and speech evaluation protocols, ultimately leading to more reliable perceptual ratings and a better understanding of the perceptual qualities of pathological voices.

Adolescent↗

PubMed1993

Measurement of Young's modulus in the in vivo human vocal folds.

Currently, surgeons have no objective means to evaluate and optimize results of phonosurgery intraoperatively. Instead, they usually judge the vocal folds subjectively by visual inspection or by listening to the voice. This paper describes a new device that measures Young's (elastic) modulus values for the human vocal fold intraoperatively. Physiologically, the modulus of the vocal fold may be important in determining the nature of vocal fold vibration in normal and pathologic states. This study also reports the effect of recurrent laryngeal nerve stimulation on Young's modulus of the human vocal folds, measured by means of transcutaneous nerve stimulation techniques. Young's modulus increased with increases in current stimulation to the recurrent laryngeal nerve. Ultimately, Young's modulus values may assist surgeons in optimizing the results of various phonosurgeries.

Adult↗

PubMed1993

Effect of tension, stiffness, and airflow on laryngeal resistance in the in vivo canine model.

This study used an in vivo canine model of phonation to determine the effects of airflow on glottal resistance at low, medium, and high levels of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) stimulation. Static and dynamic trials of changing airflow were used to study the effects of airflow on glottal resistance during phonation. As reported previously, glottal resistance varies inversely as a function of airflow. Increasing levels of RLN stimulation resulted in a statistically significant increase in glottal resistance for each level of airflow evaluated. Variation in SLN stimulation had no statistically effects on the relationship between flow and resistance. At airflow rates greater than 590 milliliters per second (mL/s), glottal resistance approached 0.1 mm Hg per mL/s for all levels of RLN and SLN stimulation tested. These data support the collapsible tube model of phonation.

Airway Resistance↗

PubMed1993

Function of the thyroarytenoid muscle in a canine laryngeal model.

Fundamental frequency is controlled by contraction of the thyroarytenoid (TA) and cricothyroid (CT) muscles. While activity of the CT muscle is known to tense and thin the vocal folds, little is known about the effect of the TA muscle on vocal fold vibration. An in vivo canine laryngeal model was used to examine the role of the TA muscle in controlling phonation. Isolated TA muscle activation was obtained by stimulating sectioned terminal TA branches through small thyroid cartilage windows. Subglottic pressure measures, electroglottographic and photoglottographic signals, and acoustic signals were obtained in 5 mongrel dogs during dynamic and static variations in TA muscle activity. Results indicated that TA muscle activation is a major determinant in sudden shifts from high-frequency to modal phonation. Subglottic pressure increased and open quotient decreased gradually with increasing TA activation.

Animals↗

PubMed1993

Function of the posterior cricoarytenoid muscle in phonation: in vivo laryngeal model.

The function of the posterior cricoarytenoid (PCA) muscle in phonation has not been well documented. To date, several electromyographic studies have suggested that the PCA muscle is not simply an abductor of the vocal folds, but also functions in phonation. This study used an in vivo canine laryngeal model to study the function of the PCA muscle. Subglottic pressure and electroglottographic, photoglottographic, and acoustic waveforms were gathered from five adult mongrel dogs under varying conditions of nerve stimulation. Subglottic pressure, fundamental frequency, sound intensity, and vocal efficiency decreased with increasing stimulation of the posterior branch of the recurrent laryngeal nerve. These results suggest that the PCA muscle not only acts to brace the larynx against the anterior pull of the adductor and cricothyroid muscles, but also functions inhibitorily in phonation by controlling the phonatory glottal width.

Animals↗

PubMed1993

Determination of vocal fold mucosal wave velocity in an in vivo canine model.

The vocal fold traveling wave is essential to normal voice production. The present investigation examined whether the velocity of the traveling wave (TWV) could be consistently determined in an in vivo canine model and if traveling wave velocity is affected by changes in the amplitude of recurrent laryngeal nerve stimulation (RLNS) and superior laryngeal nerve stimulation (SLNS). The results showed that traveling wave velocity increased with an increase in recurrent laryngeal nerve stimulation at low constant superior laryngeal nerve stimulation, but was poorly correlated with increases in recurrent laryngeal nerve stimulation at a high level of superior laryngeal nerve stimulation. Furthermore, traveling wave velocity was significantly correlated with superior laryngeal nerve stimulation at constant recurrent laryngeal nerve stimulation. This study demonstrated the feasibility of objectively measuring traveling wave velocity in vivo.

Air↗

PubMed1992

Individual differences in voice quality perception.

Sixteen listeners (10 expert, 6 naive) judged the dissimilarity of pairs of voices drawn from pathological and normal populations. Separate nonmetric multidimensional scaling solutions were calculated for each listener and voice set. The correlations between individual listeners' dissimilarity ratings were low. However, scaling solutions indicated that each subject judged the voices in a reliable, meaningful way. Listeners differed more from one another in their judgments of the pathological voices (which varied widely on a number of acoustic parameters) than they did for the normal voices (which formed a much more homogeneous set acoustically). The acoustic features listeners used to judge dissimilarity were predictable from the characteristics of the stimulus sets: only parameters that showed substantial variability were perceptually salient across listeners. These results are consistent with prototype models of voice perception. They suggest that traditional means of assessing listener reliability in voice perception tasks may not be appropriate, and highlight the importance of using explicit comparisons between stimuli when studying voice quality perception.

Adult↗

PubMed1992

Laryngeal paralyses: theoretical considerations and effects on laryngeal vibration.

The neurological causes of vocal fold paralyses have been well documented. However, the effect of these disorders on laryngeal vibration is not well understood. A theoretical four-mass model of the larynx, based on the work of Ishizaka and Isshiki (1976) and Koizumi, Taniguchi, and Hiromitsu (1987), was developed and adapted to simulate laryngeal biomechanical behavior. The model was used to evaluate various states of asymmetric laryngeal vibration. Input parameters that relate observed laryngeal function and model simulation were developed. Laryngeal paralyses were simulated by their predicted effect on these parameters. Simulations were compared with available data on glottal vibration in laryngeal paralyses. Complex modes of vibration were seen with certain combinations of asymmetrical lower mass stiffness and initial glottal gap.

Computer Simulation↗

PubMed1990

Listener experience and perception of voice quality.

Five speech-language clinicians and 5 naive listeners rated the similarity of pairs of normal and dysphonic voices. Multidimensional scaling was used to determine the voice characteristics that were perceptually important for each voice set and listener group. Solution spaces were compared to determine if clinical experience affects perceptual strategies. Naive and expert listeners attended to different aspects of voice quality when judging the similarity of voices, for both normal and pathological voices. All naive listeners used similar perceptual strategies; however, individual clinicians differed substantially in the parameters they considered important when judging similarity. These differences were large enough to suggest that care must be taken when using data averaged across clinicians, because averaging obscures important aspects of an individual's perceptual behavior.

Clinical Competence↗

PubMed1989

Voice perception deficits: neuroanatomical correlates of phonagnosia.

Voice perception (recognition of familiar voices and discrimination of unfamiliar voices) was studied in brain-damaged patients and normal controls. Left- and right-brain-damaged subjects were tested on familiar voices (25 famous males) and 26 pairs of unfamiliar voices. Deficits in recognizing familiar voices were significantly correlated with right-hemisphere damage; discrimination of unfamiliar voices was worse in both clinical groups than in normal controls. Computerized tomographic scans indicated that an intact right parietal-lobe was present in all cases of normal voice recognition, while right parietal-lobe damage was significantly correlated with a deficit in voice recognition. Temporal-lobe damage of either hemisphere was associated with a voice discrimination deficit.

Adult↗

PubMed1989

Long-term memory for unfamiliar voices.

From a sample of young male Californians, ten speakers were selected whose voices were approximately normally distributed with respect to the "easy-to-remember" versus "hard-to-remember" judgments of a group of raters. A separate group of listeners each heard one of the voices, and, after delays of 1, 2, or 4 weeks, tried to identify the voice they had heard, using an open-set, independent-judgment task. Distributions of the results did not differ from the distributions expected under the hypothesis of independent judgments. For both "heard previously" and "not heard previously" responses, there was a trend toward increasing accuracy as a function of increasing listener certainty. Overall, heard previously responses were less accurate than not heard previously responses. For heard previously responses, there was a trend toward decreasing accuracy as a function of delay between hearing a voice and trying to identify it. Information-theoretic analysis showed loss of information as a function of delay and provided means to quantify the effects of patterns of voice confusability. Signal-detection analysis revealed the similarity of results from diverse experimental paradigms. A "prototype" model is advanced to explain the fact that certain voices are preferentially selected as having been heard previously. The model also unites several previously unconnected findings in the literature on voice recognition and makes testable predictions.

Adult↗

PubMed1988

Hemispheric specialization for voice recognition: evidence from dichotic listening.

To measure lateralization of voice recognition abilities in normal subjects, listeners identified both the speaker (a famous male) and the word spoken on each trial in a dichotic listening paradigm. The voice identification task resulted in a zero ear advantage, which differed significantly from the significant right ear advantage found for word identification. This suggests that voice and word information, although carried in the same auditory signal, engage different cerebral mechanisms.

Attention↗

PubMed1988

Phonagnosia: a dissociation between familiar and unfamiliar voices.

A dissociation between facial recognition and facial discrimination is well known, but investigations of "phonagnosia" (impairment of voice recognition and discrimination) have not been pursued. Using familiar and unfamiliar voices as stimuli, a marked difference between the ability to recognize familiar voice and the ability to discriminate between unfamiliar voices was identified in five patients, and a sixth showed a severe impairment in both tasks. Clinical and radiologic findings in these cases suggest that recognition of familiar voices is impaired by damage to inferior and lateral parietal regions of the right hemisphere, whereas impairment of voice discrimination abilities is associated with temporal lobe damage of either hemisphere. This dissociation of recognition and discrimination of the human voice suggests that these two functions are mediated by different brain structures and may contribute differentially clinical syndromes.

Aged↗