Hans F. Mahieu

Deviant vocal fold vibration as observed during videokymography : the effect on voice quality

Videokymographic images of deviant or irregular vocal fold vibration, including diplophonia, the transition from falsetto to modal voice, irregular vibration onset and offset, and phonation following partial laryngectomy were compared with the synchronously recorded acoustic speech signals. A clear relation was shown between videokymographic image sequences and acoustic speech signals, and the effect of irregular or incomplete vocal fold vibration patterns was recognized in the amount of perceived breathiness and roughness and by the harmonics-to-noise ratio in the speech signal. Mechanisms causing roughness are the presence of mucus, phase differences between the left and right vocal fold, and short-term frequency and amplitude modulation. It can be concluded that the use of simultaneously recorded videokymographic image sequences and speech signals contributes to the understanding of the effect of irregular vocal fold vibration on voice quality.

Malignant lymphoma of mucosa-associated lymphoid tissue in the larynx

Abstract A 36-year-old woman was referred to the department of Otolaryngology / Head and Neck Surgery, University Hospital Vrije Universiteit, because of complaints of hoarseness. A submucosal swelling of the right ventricular fold was found that was subsequently biopsied. Histopathological examination showed a low-grade B-cell non-Hodgkin’s lymphoma of mucosa-associated lymphoid tissue (MALT). Treatment consisted of local radiotherapy (to 2800 cGy). During the 2-year follow-up to date there has been no evidence of recurrent disease. To our knowledge, only four cases of MALT lymphomas in the larynx have been reported. The clinical behavior of MALT lymphoma is clearly quite distinct and requires proper recognition to prevent inadvertent misdiagnosis or overtreatment.

LONG-TERM RESULTS OF ORGAN PRESERVATION IN CHONDROSARCOMA OF THE CRICOID

Abstract Chondrosarcoma of the larynx is rare. The posterolateral lamina of the cricoid cartilage is the site most commonly involved. Although the symptomology, radiological and histopathological diagnostic features are well known, the condition continues to be diagnosed late and recurrences after excision are common. In general, radical surgical excision can result in long-term remission, although prognosis is related to the histopathological grade of the tumor. While a conservative surgical approach in low-grade tumors is justified, unexplained hoarseness, unilateral vocal cord paralysis and dyspnea requires CT scan examination.

Voice in early glottic cancer compared to benign voice pathology

The purpose of this study is to compare (Dutch) Voice Handicap Index (VHIvumc) scores from a selected group of patients with voice problems after treatment for early glottic cancer with patients with benign voice disorders and subjects from the normal population. The study included a group of 35 patients with voice problems after treatment for early glottic cancer and a group of 197 patients with benign voice disorders. Furthermore, VHI scores were collected from 123 subjects randomly chosen from the normal population. VHI reliability was high with high internal consistency and test–retest stability. VHI scores of glottic cancer patients were similar to those of patients with voice problems due to benign lesions. Both groups of patients were clearly deviant from the normal population. Within the normal population, 16% appeared to have not-normal voices. Based on ROC curves a cut-off score of 15 points was defined to identify patients with voice problems in daily life. A clinical relevant difference score of 10 points was defined to be used for individual patients and of 15 points to be used in study designs with groups. Patients with voice problems after treatment for early glottic cancer encounter the same amount of problems in daily life as the other voice-impaired patients. The VHI proved to be an adequate tool for baseline and effectiveness measurement of voice.

Design and in vitro testing of a voice-producing element for laryngectomized patients.

A voice-producing element has been developed to improve speech quality after laryngectomy. The design process started with the formulation of a list of requirements. The lip principle has the best potential for fulfilling the requirements. A numerical model was made to find the optimal geometry of an element based on the lip principle. Extensive in vitro tests were performed to check all requirements. For this a test set-up with realistic acoustic and aerodynamic properties was developed. Results show that the protruding lip length dominates fundamental frequency, cross-sectional area dominates flow resistance and relation between flow and fundamental frequency. Most requirements have been fullfilled; both for males and females a potentially good functioning prototype could be selected. Clinical experiments will be performed to confirm the quality of the voice-producing prosthesis.

Communicative suitability of voice following radiotherapy for T1 glottic carcinoma: testing the reliability of a rating instrument.

The objective of the study was to determine whether a communicative suitability rating instrument could be used in a meaningful way to assess functionality of voice following radiotherapy for T1 glottic cancer. Seventeen naive listeners judged the suitability of voice of a patient group with T1 glottic carcinoma (n = 20) just before treatment, a group of patients (n = 40) after radiotherapy, and a matched control group (n = 20) of normal speakers. Listeners rated suitability on a 10-point scale for 10 speaking situations, which supposedly make different demands. In order to validate scores on communicative suitability, ratings were related to perceptual voice quality evaluations and videolaryngostroboscopic evaluations. Results indicate that the concept of measuring listener judgments of communicative suitability of voice is basically sound. Raters are reliable and can discriminate between groups of normal and pathological voices. Patients with T1 glottic carcinoma (assessed before the start of treatment) have on average the least suitable voices. Following radiotherapy suitability is, on average, improved, but does not approach the suitability of normal voices. Ratings on communicative suitability were clearly related to perceptual voice quality aspects and videolaryngostroboscopic evaluations. A subset of three communicative suitability rating scales is recommended as part of the protocol for evaluating voice outcome after radiotherapy for early glottic cancer, besides perceptual evaluation of voice quality by trained and naive raters, videolaryngostroboscopy, acoustical analyses, and self-ratings of vocal performance.

Alternative Voice After Laryngectomy Using a Sound-Producing Voice Prosthesis

Objective To improve the voice quality of female laryngectomees and/or laryngectomees with a hypotonic pharyngoesophageal (PE) segment by means of a pneumatic artificial source of voice incorporated in a regular tracheoesophageal (TE) shunt valve.

Long-term results of laryngeal suspension and upper esophageal sphincter myotomy as treatment for life-threatening aspiration.

Objectives: We evaluated the long-term results of laryngeal suspension and upper esophageal sphincter (UES) myotomy in patients with life-threatening aspiration. Methods: In the period 1995 to 2004, 17 patients with severe aspiration caused by insufficient laryngeal elevation and absent or negligible pharyngeal constrictor muscle activity during deglutition resulting in aspiration pneumonia were surgically treated with a laryngeal suspension procedure and UES myotomy. Preoperative and postoperative videofluoroscopy was performed to assess swallowing and aspiration. Results: In 9 of the 17 patients, long-term (more than 1 year) full oral intake without aspiration was achieved. Three other patients demonstrated improvement of deglutition with partial restoration of oral intake with adjusted food consistency, but remained partly dependent on gastrostomy feeding for adequate nutrition. Two patients no longer had cases of aspiration pneumonia, but were unable to achieve even modified oral intake. Three patients finally underwent total laryngectomy — 2 of them after initial successful full oral intake without aspiration but with recurrent aspiration as a result of progression of neuromuscular disease. None of the patients succumbed to aspiration pneumonia. Conclusions: In most of our patients, life-threatening aspiration was successfully treated by UES myotomy and laryngeal suspension with restoration of oral intake.

Aero-acoustics of silicone rubber lip reeds for alternative voice production in laryngectomees

To improve voice quality after laryngectomy, a small pneumatic sound source to be incorporated in a regular tracheoesophageal shunt valve was designed. This artificial voice source consists of a single floppy lip reed, which performs self-sustaining flutter-type oscillations driven by the expired pulmonary air that flows through the tracheoesophageal shunt valve along the outward-striking lip reed. In this in vitro study, aero-acoustic data and detailed high-speed digital image sequences of lip reed behavior are obtained for 10 lip configurations. The high-speed visualizations provide a more explicit understanding and reveal details of lip reed behavior, such as the onset of vibration, beating of the lip against the walls of its housing, and chaotic behavior at high volume flow. We discuss several aspects of lip reed behavior in general and implications for its application as an artificial voice source. For pressures above the sounding threshold, volume flow, fundamental frequency and sound pressure level generated by the floppy lip reed are almost linear functions of the driving force, static pressure difference across the lip. Observed irregularities in these relations are mainly caused by transitions from one type of beating behavior of the lip against the walls of its housing to another. This beating explains the wide range and the driving force dependence of fundamental frequency, and seems to have a strong effect on the spectral content. The thickness of the lip base is linearly related to the fundamental frequency of lip reed oscillation.

Female-pitched sound-producing voice prostheses - initial experimental and clinical results

Abstract In order to improve voice quality in female laryngectomees and/or laryngectomees with a hypotonic pharyngo-oesophageal segment, a sound-producing voice prosthesis was designed. The new source of voice consists of either one or two bent silicone lips which perform an oscillatory movement driven by the expired pulmonary air that flows along the outward-striking lips through the tracheo-oesophageal shunt valve. Four different prototypes of this pneumatic sound source were evaluated in vitro and in two female laryngectomees, testing the feasibility and characteristics of this new mechanism for alternative alaryngeal voice production. In vivo evaluation included acoustic analyses of both sustained vowels and read-aloud prose, videofluoroscopy, speech rate, and registration of tracheal phonatory pressure and vocal intensity. The mechanism proved feasible and did not result in unacceptable airflow resistance. The average pitch of voice increased and clarity improved in female laryngectomees. Pitch regulation of this prosthetic voice is possible with sufficient modulation to avoid monotony. The quality of voice attained through the sound-producing voice prostheses depends on a patient’s ability to let pulmonary air flow easily through the pharyngo-oesophageal segment without evoking the low-frequency mucosal vibrations that form the regular tracheo-oesophageal shunt voice. These initial experimental and clinical results provide directions for the future development of sound-producing voice prostheses. A single relatively long lip in a container with a rectangular lumen that hardly protrudes from the voice prosthesis may have the most promising characteristics.