Acoustic analysis of voice in amyotrophic lateral sclerosis: a longitudinal case study

Acoustic measures of phonatory instability (coefficient of variation for amplitude, coefficient of variation for frequency, shimmer, jitter, and harmonics-to-noise ratio), phonatory limits (maximum fundamental frequency range and maximum duration of vowel phonation), and the nasal-oral amplitude ratio were measured five times throughout a 6-month period from the phonation of a 69-year-old male patient with amyotrophic lateral sclerosis (ALS), an age- and sex-matched control subject, and on one occasion from a 16-subject control group matched to the patient in age and sex. The patient was free of vocal symptoms at the initiation of the study. When compared to the other recording sessions, the final recording of the ALS patient was characterized by increased coefficient of variation for amplitude, increased coefficient of variation for frequency, increased shimmer, increased jitter, reduced harmonics-to-noise ratio, and reduced maximum vowel duration. These acoustic manifestations of increased phonatory instability and reduced phonatory limits over time were in contrast to the consistency observed in the phonation of the longitudinal control subject and were outside the range of plus or minus one standard deviation on most acoustic variables when compared to the control group. These findings support the potential use of acoustic analysis in reflecting progression of ALS and suggest the need for further studies to investigate the relationship between acoustic analysis of voice and manifestations of neurological disease.     

A continuous-flow model for phonatory reaction time

The purpose of this study was to validate a proposed continuous-flow model of phonatory reaction time by investigating the temporal order of selected laryngeal and neurophysiological events involved in a phonatory reaction time task. Ten normal speakers participated in a phonatory reaction time task. Laryngeal positioning movements prior to vocal fold closure (laryngeal shift) and onset of vocal fold vibration (acoustic onset) were recorded with an electroglottograph. P300 brain potentials were collected simultaneously, and they served as an index of a central process underlying reaction time. The obtained temporal ordering of laryngeal shift, P300, and acoustic onset supported a continuous-flow model of phonatory reaction time. Use of this model might yield information that is more accurate in explaining physiological function and more precise in describing temporal patterning than the serial model.     

Acoustic variations in adductor spasmodic dysphonia as a function of speech task.

Acoustic phonatory events were identified in 14 women diagnosed with ADSD and compared to those of 14 women age-matched (+/-2 years) with no evidence of vocal pathology/dysfunction. The three acoustic parameters examined during sustained vowel production and reading included phonatory breaks, aperiodicity, and frequency shifts. Intra- and intermeasurer correlations showed high reliability for the measures. Findings indicated that those with ADSD produced a greater frequency of aberrant acoustic events than the controls during both tasks. For the group with ADSD, the amount and type of each event also varied with utterance type. The sustained vowel sample produced by those with ADSD consisted of a greater percentage of aperiodic segments followed by phonatory breaks and frequency shifts. During reading, frequency shifts were the predominant acoustic event, followed by phonatory breaks and aperiodicity. The advantage of segmenting the acoustic waveform into these measures and the relevancy of examining intertask performances by those with ADSD is discussed.     

Articulatory changes following treatment of muscle tension dysphonia: preliminary acoustic evidence

PURPOSE: Primary muscle tension dysphonia (MTD), a voice disturbance that occurs in the absence of structural or neurological pathology, may respond to manual circumlaryngeal techniques, which ostensibly alter the posture of the larynx and/or the configuration of the vocal folds without directly targeting supralaryngeal articulatory structures. Although the phonatory benefits of these techniques have been documented previously, this investigation examined whether acoustic evidence exists for articulatory changes accompanying successful management. METHOD: In this retrospective study of a clinical database, pre- and post-treatment speech samples from 111 women with MTD were analyzed for acoustic evidence of supraglottal vocal tract changes associated with voice improvement, which was confirmed by perceptual ratings of dysphonia severity. The slopes of the first and second formants in diphthongs, as well as global measures of speech timing were acquired. Twenty younger females with normal voices were recorded twice, across a similar time-span to the disordered speakers, to allow comparisons in performance. RESULTS: Repeated measures analysis of variance was used to evaluate changes accompanying treatment. Significant time by group interactions for /I/ F2 slope, /eI/ F2 slope, sample duration, and speaking time ratio were observed. As compared to the controls, diphthong second formant transitions increased in slope, and timing measures showed increases in speech continuity for the speakers with MTD. CONCLUSIONS: Collectively, these preliminary findings suggest that individuals with MTD experience changes in both articulatory and phonatory behavior following successful treatment that targets the larynx.     

The outcome of hydration in functional dysphonia

Functional dysphonia has high prevalence among professional voice users. Different aspects should be considered in vocal therapy. One of them is hydration. The aim of the present study is to assess the effect of hydration on a few aspect of vocal dysfunction. 75 subjects were distributed into three different groups. 23 participated as a control group, 27 received hydration treatment and 25 received hydration treatment plus voice training. Dryness, mucosity, phonatory effort, hoarseness, fundamental frequency (Fo), maximum phonatory time (MPT), time of speech and laryngeal status were the variables evaluated at time 0 and 14 days later, immediately after the completion of the treatment of each group. Statistical differences regarding dryness (p = 0.003) and hoarseness (p = 0.033) were found between the control group and the groups receiving treatment. There were no statistical differences in severity and frequency of variables measured at time 0 at 14 days later in the control group. However, all variables except laryngeal status, improved significantly in the groups receiving hydration alone. Only clinical variables improved in the combined group. These findings indicated a therapeutic benefit of hydration, with or without voice training, for functional dysphonia. Further studies using acoustic and stroboscopic analysis are required in order to define the effect of hydration on the compliance of glottic sphincter.     

Dynamic aspects of phonatory control in spasmodic dysphonia

To understand the voluntary laryngeal movement disorder in spasmodic dysphonia (SD), SD patients were compared with normal controls on speech tasks with different laryngeal motor-control demands. Nine patients with idiopathic chronic SD and no other speech, otolaryngologic, neurologic, or psychiatric disorders were compared with 15 control subjects who were free of such disorders. Speech production tasks required different degrees of dynamic and precise control of vocal fold movement. Phonatory off times were increased in the SD patients, while maximum phonation time, phonatory on time, frequency and intensity control, and reaction times for CV syllables were not affected. On a reaction-time task, the onset of laryngeal movement was not delayed in the SD patients, however, the time between the onset of laryngeal movement and phonatory onset was significantly increased in the SD patients in comparison with the controls. Therefore, SD patients had no difficulty with the onset of laryngeal movement but were slow to achieve phonation, indicating a movement-control disorder affecting vocal fold adduction for phonation onset.     

Sensitivity of the neuromagnetic N100m deflection to spectral bandwidth: a function of the auditory periphery?

The amplitude of the auditory evoked field (AEF) component N100m in response to tonal stimuli of varying spectral bandwidth and periodicity was compared with simulated peripheral activity patterns of the auditory nerve (AN). The AEF of ten subjects was recorded with a 37-channel axial gradiometer system (four independent measurement sessions per hemisphere). The simulated peripheral activity was characterized using measures derived from spike probabilities of the AN. Stimuli were pure tones, narrow-band harmonic complex tones (spectrum: 4-4.8 kHz), and broad-band harmonic complex tones (spectrum: 800 Hz-4.8 kHz) with periodicities of 100, 200, and 400 Hz. The intensity of all stimuli was set to 65 dB above the absolute thresholds. Both the simulated AN activity and measured cortical response amplitudes increased consistently with spectral bandwidth. This suggests that the enhanced sensitivity of the N100m amplitude to broad-band complex tones is to some extent a function of the auditory periphery.     

Subjective audiological tests and transient evoked otoacoustic emissions in patients with rheumatoid arthritis: analysis of the factors affecting hearing levels

We investigated hearing functions in patients with rheumatoid arthritis (RA) using audiological tests and transient evoked otoacoustic emissions (TEOAEs). The study group consisted of 20 adult patients with RA (7 males, 13 females); 20 adult healthy subjects without RA (7 males, 13 females) were recruited as controls. All patients were evaluated by pure tone audiometry, high frequency audiometry, tympanometry and TEOAEs. There were no statistical differences between the study and control groups with respect to the pure tone and high frequency audiometries. TEOAE results of 1.0–2.0 kHz % and of 1.5 and 3.0 kHz amplitude values were significantly lower, and ipsilateral stapes reflex threshold value at 1.0 kHz was significantly higher in the study group when compared to respective values in the control group. In elderly patients and those with longer disease duration, RA nodules and higher methotrexate cumulative doses, hearing thresholds increased and TEOAE values decreased. In active stage of the disease, hearing thresholds diminished and in higher Brinkman Index values, TEOAE values decreased. Compliance values decreased in patients with higher Ritchie Articular Index, C-reactive protein, erythrocyte sedimentation rate and platelet counts, and longer disease duration. Sensorineural hearing loss is generally observed in patients with RA, and this condition may be detected by TEOAEs in an early period of the disease. Inflammation during the active stage of the disease and the subsequent fibrosis may cause conductive hearing loss of varying degrees. In those patients detected as having initiation of TEOAE decrease, vasodilator treatment and antioxidant drugs may be useful in protecting the inner ear.     

Lidocaine block of the recurrent laryngeal nerve in adductor spasmodic dysphonia: a multidimensional assessment

OBJECTIVES/HYPOTHESIS: Lidocaine block of the recurrent laryngeal nerve (RLN) has been reported as a procedure for surgical selection of patients with adductor spasmodic dysphonia (ADSD). However, its effects on phonation have not been rigorously assessed in a prospective fashion using strict entry criteria and multiple measures of phonatory function. This investigation assessed the phonatory effects of RLN lidocaine block in ADSD to explore its potential as a diagnostic tool. STUDY DESIGN: Single group, pre/postexperimental trial. METHODS: Twenty-one consecutive patients with suspected ADSD underwent unilateral RLN block, causing temporary ipsilateral vocal fold paralysis. Voices were recorded before and during the block. Patients completed self-ratings of overall level of dysphonia severity, vocal effort, and laryngeal tightness. Blinded listeners completed auditory-perceptual ratings, and the frequency of phonatory breaks was acoustically analyzed. RESULTS: During the block, patients reported significant reductions on overall severity (P = .045), vocal effort (P < .001), and laryngeal tightness (P = .002). Listeners rated the voices during the block as significantly more breathy (P < .001), less strained (P < .001), and less severe (P = .059). Acoustic analysis confirmed significantly fewer phonatory breaks during the block (P < .001). Patient-based ratings of improvement were more consistent than listener ratings, and reduction in overall severity correlated with perceived breathiness. CONCLUSIONS: Although individuals varied in their outcomes, group results suggest that response to RLN lidocaine block warrants further study as a possible diagnostic tool in ADSD.     

Vocal fold deposits in autoimmune disease — an unusual cause of hoarseness

The objective of this study was to evaluate the symptoms and clinical characteristics in patients with autoimmune vocal fold deposits. Fourteen patients underwent videolaryngostroboscopic examination and voice recording. Eleven of the 14 patients underwent rheumatological examination. In all cases, endoscopic examination showed transverse white‐yellow band lesions in the middle of the membranous portion of the vocal folds. In most cases, the lesions were bilateral but not exactly opposing each other. The most common voice characteristics were instability and intermittent aphonia. Inflammatory disease was present in 10 patients; five of these had rheumatoid arthritis (RA). No immunological signs common for all patients could be found. The histological examination was consistent with rheumatoid nodules. Vocal fold deposits, occurring most often in patients with RA, is an uncommon cause of hoarseness. Because the patients may have hoarseness as their primary symptom, it is important for otolaryngologists to be familiar with this disorder.     

Vocal fold deposits in autoimmune disease--an unusual cause of hoarseness

The objective of this study was to evaluate the symptoms and clinical characteristics in patients with autoimmune vocal fold deposits. Fourteen patients underwent videolaryngostroboscopic examination and voice recording. Eleven of the 14 patients underwent rheumatological examination. In all cases, endoscopic examination showed transverse white-yellow band lesions in the middle of the membranous portion of the vocal folds. In most cases, the lesions were bilateral but not exactly opposing each other. The most common voice characteristics were instability and intermittent aphonia. Inflammatory disease was present in 10 patients; five of these had rheumatoid arthritis (RA). No immunological signs common for all patients could be found. The histological examination was consistent with rheumatoid nodules. Vocal fold deposits, occurring most often in patients with RA, is an uncommon cause of hoarseness. Because the patients may have hoarseness as their primary symptom, it is important for otolaryngologists to be familiar with this disorder.     

Consistency of voice produced by patients with adductor spasmodic dysphonia: a preliminary investigation.

Adductor spasmodic dysphonia (ADSD) is an idiopathic focal laryngeal movement disorder causing involuntary and uncontrollable spasms in the vocal fold musculature, primarily during voice onset. Although phonatory instability has been reported through clinical observation and empirical study, no examination of phonatory performance consistency in ADSD has been done. Phonatory instability refers to phonatory unsteadiness and has been previously defined by the presence of acoustic aberrations during speech. Performance consistency pertains to variations in these phonatory aberrations across repeated trials or over time. This study focused on the phonatory performance consistency of those with ADSD by using three acoustic measures of phonatory instability. Twenty patients with ADSD were recorded during three trials of reading a standard passage. Eight of the 20 patients were recorded twice during two separate recording sessions held approximately 6 months apart.The number of phonatory breaks, frequency shifts, and aperiodic segments were the dependent measures. Data were subjected to inferential statistical analysis to test for significant differences among the measures in two conditions: across three trials produced within one recording session and across multiple trials produced during two distinct recording sessions. No significant differences were found for any of the measures either as a function of trials recorded on the same day or across the two recording sessions. The data suggest a need for describing phonatory instability and performance consistency as separate entities with regard to neurological voice disorders.     

Effects of vocal task and respiratory phase on prephonatory chest wall movements.

A vocal reaction time paradigm was used to explore prephonatory respiratory kinematics. Movements of the rib cage and abdomen were recorded prior to production of utterances differing in length and intensity, and vocal responses were elicited in different phases and volumes of the quiet breathing cycle. A velocity threshold was used to distinguish prephonatory adjustments from the cyclical movements of the chest wall that are characteristic of quiet breathing. The results suggest that a variety of prephonatory kinematic events can occur prior to initiation of vocalization in response to a stimulus. Further, prephonatory movements appear to be adaptive in that they are influenced by the length of the utterance to be spoken and the respiratory volume at the time of voice initiation.     

Clearing microvascular lesions of the true vocal fold with the KTP/532 laser

Although used for treating vascular malformations, KTP (532 nm) lasers have not been used to treat microvascular lesions of the vocal fold. The efficiency of KTP laser operation in the continuous mode with a 0.4- or 0.6-mm beam (1- to 2-W aim for 3 to 7 seconds delivering a total energy of 3 to 7 J) was studied retrospectively in patients with microvascular lesions of the vocal fold (n = 14). The perceptual acoustic, phonatory function, and videolaryngostroboscopic data were evaluated before and after operation in 10 patients. At follow-up (mean, 7 months), the results were excellent in all patients. Their phonatory function (jitter, shimmer, grade, breathiness, and roughness) significantly improved (p < .01). The videolaryngostroboscopic rating showed significant improvement in the amplitude of vocal fold vibration and excursion of the mucosal wave (p < .05). No postoperative recurrence or complications were noted. The KTP laser operation is a useful, cost-effective, and time-saving procedure and can be considered as an option in management of patients with microvascular lesions of the vocal fold, particularly those with repeated hemorrhages. Because the operation is easy (compared to other surgical methods) and has no major side effects, the prospect of total patient recovery is excellent.     

Fixation of the crico-arythenoid joints in rheumatoid arthritis--preliminary report

Rheumatoid arthritis (RA) is a systemic disease of connective tissue which affects joints lined with synovial membrane. Laryngeal joints also have such a structure. Among all reasons leading to their inflammation rheumatoid arthritis is mentioned on the first place. In larynx RA mostly affects cricoarythenoid joints (CA). RA of the CA joints is found in 27% to 78% suffering from RA. In the acute phase of the disease patients complain of burning and foreign body sensation in the throat, hoarseness, pain on speaking, voice fatigability, problems with swallowing. Chronic RA of the CA joints can lead to their fixation and dyspnoea, requiring emergency tracheotomy. According to the literature, this state occurs in 10% to 25% patients suffering from RA. A case of 75 years old woman is presented, who was admitted to our Clinic with severe inspiratory dyspnoea requiring tracheotomy. She was suffering from RA for 26 years. She complained of effort dyspnoea, problems with swallowing and tightness sensation in the throat for 4 years. Patient complained also about cervical spine pain, upper right extremity and knee joint periodic oedema. The patient was suffering from so severe lower extremities pain and rheumatoid changes in knee joints that she had to walk on crutches. Little hands' joints were deformed with significant ulnarisation. Videolaryngostroboscopic examination showed no movement in CA joints, paramedian position of the vocal folds and narrowing of the glottic rim to 1.5 mm. Phonatory mobility of the vocal folds was preserved. Electromiographic examination of the internal laryngeal muscles made a) during phonation--showed bilateral normal bioelectrical record from thyroarythenoid muscles, b) at rest--there was no denervation activity. In computerized tomography study no degenerative changes in CA joints were found. On the basis of clinical view and examinations results, there was considered that fixation in CA joints was due to degenerative changes, which were the result of their rheumatoid inflammation. It was emphasized that this subject has been mentioned only several times in laryngological and phoniatric handbooks and in few articles.     

Quantitative voice analysis in the assessment of bulbar involvement in amyotrophic lateral sclerosis

Bulbar and pseudobulbar symptoms are diagnostic criteria of amyotrophic lateral sclerosis (ALS). One of the earliest symptoms of bulbar involvement is voice deterioration. Until now voice assessment in ALS patients has been done mainly by perceptual analysis. The objective parameters, including acoustic measures, one aerodynamic measure and the maximal phonation time, have been measured only in a few small series of patients. The first purpose of this prospective study was to determine which vocal parameters discriminate ALS patients with bulbar involvement from control patients. The second was to identify sensitive parameters for early detection of voice deterioration due to bulbar involvement in pre-symptomatic ALS patients. The voices of 63 female ALS patients, including 40 with bulbar symptoms (sALS patients) and 23 without bulbar symptoms (aALS patients), were studied using an objective voice analysis system that allows simultaneous analysis of acoustic and aerodynamic parameters. Measurements were compared with those obtained in 40 normal female subjects (control patients). Five of eight acoustic parameters were significantly different among the three groups: jitter, coefficient of variation for frequency, shimmer, number of harmonics, and maximum phonatory frequency range. Three aerodynamic parameters, phonatory airflow, cycle-to-cycle variation for phonatory airflow, and coefficient of variation for phonatory airflow were significantly different between sALS patients and control patients. No aerodynamic parameter allowed discrimination between aALS patients and control patients. This study shows that acoustic parameters are more sensitive than aerodynamic parameters for early detection of bulbar involvement. Nevertheless, the measurements used can predict bulbar involvement in 73% of those in the sALS group, but only in 52% of those in the aALS group.     

Vocal Capacities in Esophageal and Tracheoesophageal Speakers

The present study investigated the vocal capacities of adult men who had undergone total laryngectomy. Esophageal (N = 10) and tracheoesophageal (N = 10) speakers were compared for the parameters maximum phonation time (MPT), maximum number of syllables that could be spoken on one air intake (SYLLS), dynamic range (DYN), frequency range (FREQ), and maximum intensity level (MIL). Statistical analyses yielded significant between-group differences for the parameters MPT, SYLLS, and MIL but not for DYN and FREQ. Thus, although the groups did not differ with respect to range of intensity and frequency measures, maximum performance on the durational and intensity measures was always less for the esophageal speakers than for the tracheoesophageal speakers. Pearson's product-moment correlations among these parameters were remarkably different for esophageal and tracheoesophageal subjects, suggesting that phonatory and aerodynamic factors interact differently in the two groups.     

On the therapeutic methods of facial bone injuries

The authors present clinicomorphological characteristics of 2293 patients with benign neoplasms of the vocal cords. Nodules predominated in females, contact granulomas in males. Histological and histochemical evidence indicates that polyp-like new growths of the vocal cords known as fibromas, angiofibromas and nodules are not tumors. They are rather edematous, edematous-fibrous and angiomatous polyps arising as a reaction of vocal cords mucosa to phonatory trauma or chemical irritants.     

Combined arytenoid adduction and laryngeal reinnervation in the treatment of vocal fold paralysis

OBJECTIVE/HYPOTHESIS: Glottal closure and symmetrical thyroarytenoid stiffness are two important functional characteristics of normal phonatory posture. In the treatment of unilateral vocal cord paralysis, vocal fold medialization improves closure, facilitating entrainment of both vocal folds for improved phonation, and reinnervation is purported to maintain vocal fold bulk and stiffness. A combination of medialization and reinnervation would be expected to further improve vocal quality over medialization alone. STUDY DESIGN: A retrospective review of preoperative and postoperative voice analysis on all patients who underwent arytenoid adduction alone (adduction group) or combined arytenoid adduction and ansa cervicalis to recurrent laryngeal nerve anastomosis (combined group) between 1989 and 1995 for the treatment of unilateral vocal cord paralysis. Patients without postoperative voice analysis were invited back for its completion. A perceptual analysis was designed and completed. METHODS: Videostroboscopic measures of glottal closure, mucosal wave, and symmetry were rated. Aerodynamic parameters of laryngeal airflow and subglottic pressure were measured. A 2-second segment of sustained vowel was used for perceptual analysis by means of a panel of voice professionals and a rating system. Statistical calculations were performed at a significance level of P = .05. RESULTS: There were 9 patients in the adduction group and 10 patients in the combined group. Closure and mucosal wave improved significantly in both groups. Airflow decreased in both groups, but the decrease reached statistical significance only in the adduction group. Subglottic pressure remained unchanged in both groups. Both groups had significant perceptual improvement of voice quality. In all tested parameters the extent of improvement was similar in both groups. CONCLUSION: The role of laryngeal reinnervation in the treatment of unilateral vocal cord paralysis remains to be established.     

The ultra-low resistance Groningen voice prosthesis: clinical experiences.

The performance of the ULR Groningen prosthesis was assessed in 21 laryngectomees. The intratracheal phonatory pressures (PITP), voice parameters (speech rate, maximal phonation time, maximal vocal intensity, dynamic vocal intensity range), device lifetime and patient's subjective acceptances were recorded and compared to identical parameters for other prostheses reported in the literature and to data obtained from an age-matched group of normal laryngeal speakers. The low airflow resistance of the ULR Groningen voice prosthesis objectively (PITP = 2.7 kPa) and subjectively leads to a low effort to phonate. Compared to "normals" maximal phonation time shows no significant difference, but speech rate, maximal vocal intensity and dynamic vocal intensity range show a significant worse outcome. The mean device lifetime of the ULR Groningen prosthesis is more than 13.6 weeks, which is comparable to other indwelling voice prostheses. In conclusion, the ULR Groningen voice prothesis enables easier tracheoesophageal phonation than the low-resistance Groningen type.