Comparison of electroglottographic and acoustic analysis of pitch perturbation.

Pitch perturbation is a measure of the cycle-to-cycle variation in vocal fold vibration. Perturbation can be assessed by means of electroglottographic or acoustic signals. The purpose of this study was to determine if these two analysis techniques are equivalent measures. The Laryngograph, an electroglottograph, and the Visi-Pitch, an acoustic analyzer, were used to measure pitch perturbation in 80 dysphonic subjects. Both instruments use Koike's formula to calculate relative average perturbation. While intra-subject variability appeared erratic, statistical analysis of intersubject data indicated that the two instruments provided an equivalent measure of pitch perturbation.

Acoustic characteristics of post-thyroplasty patients.

This study investigated changes in voice quality after thyroplasty type I in eight adults with unilateral vocal fold paralysis. A silicone rubber implant was inserted through a window in the thyroid ala and placed between the inner and outer perichondrium to externally medialize the abducted vocal fold. Measures of fundamental frequency (vocal pitch), pitch range, maximum phonation time, s/z ratio, pitch perturbation (vocal jitter), and amplitude perturbation (vocal shimmer) were made 1 to 2 weeks preoperatively and 1 month postoperatively. Postoperative voice quality was characterized by an improved pitch range, phonation time, s/z ratio, and pitch and amplitude perturbation. No change was noted in fundamental frequency. Changes in postoperative voice quality were unrelated to the subjects' preoperative age, sex, etiology, and duration of the paralysis.

Advances in non-invasive measures of vocal acoustics.

Objective assessment of vocal pitch, loudness, and quality is a crucial adjunct to endoscopy in the diagnosis and treatment of vocal pathology. Historically, this assessment was made through subjective, perceptual measures that were questionable in terms of validity and reliability. Recent advances in electronic technology now permit objective analysis of the acoustic characteristics of voice. Kay Elemetric's Visi-Pitch, DSP 5500 Digital Spectrograph, and Nasometer are representative of these new instruments and are used as illustrations in the discussion of the assessment of speech acoustics.

Non-invasive assessment of phonatory and respiratory dynamics.

Evaluation of vocal pathology and the accompanying dysphonia should include an assessment of laryngeal structure and mobility as well as respiratory dynamics. Laryngeal structure is best observed through laryngoscopy which provides an accurate assessment of the tissues and their mobility. Respiratory measures of lung volume, air-flow and pressure, and breathing dynamics are typically determined via spirometry and pneumotachography. While the above are traditional invasive procedures which interfere with normal speech production, recent advances in electronic technology have resulted in the development of non-invasive procedures to assess phonatory and respiratory dynamics. These procedures, when used as an adjunct to laryngoscopy, can provide information that is useful in the diagnosis and management of vocal tract dysfunction. The Laryngograph and Computer-Aided Fluency Establishment Trainer, described here, are examples of this new technology.

Rehabilitation of swallowing and communication following glossectomy.

Patients who have had surgical removal of part or all of the tongue are left with varying degrees of swallowing and speech deficiencies. The extent of resection, mobility of the residual tongue segment, and adequacy of the remaining structures determine the amount and type of deficiency. While communicative impairment and dysphagia commonly are seen in a rehabilitation setting, the problems of the glossectomy patient often are unique. This article reviews the anatomy and physiology of the oral and pharyngeal musculature, discusses the speech and swallowing of the glossectomy patient, and presents nursing considerations for successful rehabilitation.

Respiratory dynamics and speech intelligibility in speakers with generalized dystonia.

This study investigated aspects of respiratory function, during quiet breathing and monologue, in six adult dystonic subjects and compared the findings to a control group of four neurologically intact adults. Additionally, breathing dynamics were compared with speech intelligibility. Respiratory inductive plethysmography was used to assess breathing rate, periodicity of the breathing pattern, and inspiratory lung volume. Ear oximetry was used to assess arterial blood oxygen saturation. Speech intelligibility was rated by a panel of five judges. Breathing patterns differed between groups; the dystonic subjects showed a faster breathing rate, less rhythmic breathing pattern, decreased lung volume, and apnealike periods accompanied by a decrease in arterial blood oxygen saturation. These differences were observed during quiet breathing and monologue. Decreased speech intelligibility was strongly related to differences in breathing dynamics.