Vocal aging and the impact on daily life: a longitudinal study

Longitudinal studies on vocal aging are scarce, and information on the impact of age-related voice changes on daily life is lacking. This longitudinal study reports on age-related voice changes and the impact on daily life over a time period of 5 years on 11 healthy male speakers, age ranging from 50 to 81 years. All males completed a questionnaire on vocal performance in daily life, and perceptual and acoustical analyses of vocal quality and analyses of maximum performance tasks of vocal function (voice range profile) were performed. Results showed a significant deterioration of the acoustic voice signal as well as increased ratings on vocal roughness judged by experts after the time period of 5 years. An increase of self-reported voice instability and the tendency to avoid social parties supported these findings. Smoking males had a lower speaking fundamental frequency compared with nonsmoking males, and this seemed reversible for males who stop smoking. This study suggests a normal gradual vocal aging process with clear consequences in daily life, which should be taken into consideration in clinical practice as well as in studies concerning communication in social life.     

The singing/acting voice in the mature adult

With years of training and performance, the mature vocal performer experiences less vocal changes with aging than does his/her age peer who is not a performer. We have considered, some physical problems that may adversely influence the voice of the older performer. With some awareness and effective management of these possible problems, the negative effects on the older performer's voice can be minimized.     

Aging Thyroarytenoid and Limb Skeletal Muscle: Lessons in Contrast

Voice production is vital throughout life because it allows for the communication of basic needs as well as the pursuit and enjoyment of social encounters. Unfortunately, for many older individuals the ability to produce voice is altered. Structural and functional declines in the neuromuscular system occur with aging and likely contribute to the modification of voice. One specific target of the aging process is the thyroarytenoid (TA) muscle, the primary muscle of voice production. The objectives of this overview article are to (1) share current findings related to the aging of limb skeletal muscle, (2) identify age-related morphological and physiological features of TA muscle, (3) compare and contrast age-related changes in TA with those in limb skeletal muscle, and (4) describe therapies for reversing sarcopenia in limb muscle and consider the applicability of these therapies for addressing vocal fold atrophy and age-related voice changes. The article shares current knowledge from the basic sciences related to skeletal muscle aging and compares/contrasts typical muscle aging to TA aging. Current evidence suggests that (1) the TA muscle undergoes notable remodeling with age, (2) aging of the TA is multifactorial, resulting from a myriad of neurologic, metabolic, and hormonal changes, many of which are distinct from the age-related processes of typical limb skeletal muscle, (3) investigation of the aging of the TA and its role in the aging of voice is in its infancy, and (4) potential behavioral and nonbehavioral therapies for reversing aging of the TA must be further examined.     

Voice responses to changes in pitch of voice or tone auditory feedback

The present study was undertaken to examine if a subject's voice F0 responded not only to perturbations in pitch of voice feedback but also to changes in pitch of a side tone presented congruent with voice feedback. Small magnitude brief duration perturbations in pitch of voice or tone auditory feedback were randomly introduced during sustained vowel phonations. Results demonstrated a higher rate and larger magnitude of voice F0 responses to changes in pitch of the voice compared with a triangular-shaped tone (experiment 1) or a pure tone (experiment 2). However, response latencies did not differ across voice or tone conditions. Data suggest that subjects responded to the change in F0 rather than harmonic frequencies of auditory feedback because voice F0 response prevalence, magnitude, or latency did not statistically differ across triangular-shaped tone or pure-tone feedback. Results indicate the audio-vocal system is sensitive to the change in pitch of a variety of sounds, which may represent a flexible system capable of adapting to changes in the subject's voice. However, lower prevalence and smaller responses to tone pitch-shifted signals suggest that the audio-vocal system may resist changes to the pitch of other environmental sounds when voice feedback is present.     

Speaking fo and cepstral periodicity analysis of conversational speech in a 105-year-old woman: Variability of aging effects

We investigated speaking fundamental frequency and periodicity of voicing during conversational speech in a 105-year-old woman. Analyses revealed higher mean speaking fundamental frequency compared to previously published data obtained from elderly women. In the absence of normative data, the results of cepstrum analyses performed on vowels produced during connected speech revealed less periodicity for the 105-year-old woman's voice than for a 35-year-old woman's voice. The main finding of this study indicates that previously reported group trends regarding aging effects on mean speaking fundamental frequency of the female voice cannot simply be attributed to all elderly individuals. These results stress the importance, for clinical and research purposes, of recognizing the existence of considerable intra- as well as intersubject variability in the effects of aging on the voice.     

Harmonics-to-Noise Ratio: An Index of Vocal Aging

Distinguishing between vocal changes that occur with normal aging and those that are associated with disease is an important goal of research in voice. Several acoustic measures have been used in an attempt to illuminate the integrity of the vocal mechanism, including harmonics-to-noise ratio (HNR), jitter, and fundamental frequency (F₀). HNR is a measure that quantifies the amount of additive noise in the voice signal; jitter reflects the periodicity of vocal fold vibration. In this study, measures of HNR, jitter and F₀ were used to compare vocal function in three groups of normally speaking women: young adults, middle-aged adults, and elderly adults. Significant differences in HNR emerged between the elderly women and the other two groups. F₀ differences were also apparent between the elderly group and the two younger groups; there were no significant differences in jitter between the three groups. HNR was found to be a more sensitive index of vocal function than jitter. The significant lowering of HNR evident in the elderly speakers may be attributable in part to medications taken by the majority of these elderly subjects.     

Evaluation of Voice Pathology Based on the Estimation of Vocal Fold Biomechanical Parameters

Voice disorders are a source of increasing concern as normal voice quality is a social demand for at least one third of the population in developed countries in cases where voice is an essential resource in professional exercise. In addition, the growing exposure to certain pathogenic factors such as smoking, alcohol abuse, air pollution, and acoustic contamination, and other problems such as gastro-esopharyngeal reflux or allergy as well as aging, aggravate voice disorders. Voice pathologies justify the assignment of larger resources to prevention policies, early detection, and less aggressive treatments. Traditional pathology detection relies on perceptive evaluation methods (GRABS), acoustic analysis, and visual inspection (indirect laryngoscopy, and modern fibro-endo-stroboscopy). This article describes a method for voice pathology detection based on the noninvasive estimation of vocal cord biomechanical parameters derived from voice using specific signal processing methods. Preliminary results using records from patients showing four frequent causes of voice pathology (nodules, polyps, chronic laryngitis, and Reinke's edema) are given. The results show that the alteration (distortion, unbalance, or deviation) of cord biomechanical parameters may serve as an indicator of pathology. Statistical methods based on hierarchical clustering and principal component analysis reveal that combining biomechanical estimates with classic perturbation parameters increases the accuracy of acoustic analysis, improving the detection of voice pathology. This research could open new possibilities for noninvasive screening of vocal fold pathologies and could be used in the implantation of e-health voice care services.     

Luminescence instability of films and new organic light-emitting diodes based on zinc complexes with tetradentate Schiff bases: Influence of heating and laser irradiation

Organic light emitting diodes (OLEDs) based on zinc complexes with tetradentate Schiff bases — ZnSB [H₂SB =H₂Sal1, H₂Sal2 (derivatives of salicylic aldehyde); H₂MO1, H₂MO2 (derivatives of o-vanillin)] display reversible and irreversible electroluminescence (EL) instability. The reversible instability occurs after switching voltage on and the irreversible instability produced by UV light irradiation, heating, and aging under the ambient conditions. In view of the results obtained, the first type of instability is associated with the trap filling processes and the second type appearing at heating is possibly attributed to the changes in the interface domains. Recommendations for the evaporation and capsulation conditions are provided.     

Spectral Moments of the Long-term Average Spectrum: Sensitive Indices of Voice Change After Therapy?

Voice clinicians require an objective, reliable, and relatively automatic method to assess voice change after medical, surgical, or behavioral intervention. This measure must be sensitive to a variety of voice qualities and severities, and preferably should reflect voice in continuous speech. The long-term average spectrum (LTAS) is a fast Fourier transform-generated power spectrum whose properties can be compared with a Gaussian bell curve using spectral moments analysis. Four spectral moments describe features of the LTAS: Spectral mean (Moment 1) and standard deviation (Moment 2) represent the spectrum's central tendency and dispersion, respectively. Skewness (based on Moment 3) and kurtosis (based on Moment 4) represent the spectrum's tilt and peakedness, respectively. To examine whether the first four spectral moments of the LTAS were sensitive to perceived voice improvement after voice therapy, this investigation compared pretreatment and posttreatment voice samples of 93 patients with functional dysphonia using spectral moments analysis. Inspection of the results revealed that spectral mean and standard deviation lowered significantly with perceived voice improvement after successful behavioral management (p < 0.001). However, changes in skewness and kurtosis were not significant. Furthermore, lowering of the spectral mean uniquely accounted for approximately 14% of the variance in the pretreatment to posttreatment changes observed in perceptual ratings of voice severity (p < 0.001), indicating that spectral mean (ie, Moment 1) of the LTAS may be one acoustic marker sensitive to improvement in dysphonia severity.     

Acoustic analysis of voice in individuals with amyotrophic lateral sclerosis and perceptually normal vocal quality

Currently, early phonatory changes in amyotrophic lateral sclerosis(ALS) are not well understood. The aim of this study was to compare acoustic parameters of voice in ALS subjects who demonstrated perceptually normal vocal quality on sustained phonation with a control group. We hypothesized that objective analysis of voice would reveal significant differences on specific acoustic parameters of voice compared to the control group. Results revealed statistically significant differences between the two groups on measures related to frequency range and phonatory stability. The findings suggest that early bulbar signs affecting the laryngeal system may be present in patients with ALS before the occurrence of perceptually aberrant vocal characteristics.     

The young adult voice

Young adulthood is notable for rapid physical changes and psychosocial instability. Care of the young adult professional voice requires knowledge of the specific anatomic and physiologic changes associated with the mutational voice, as well as the effects of general growth and maturation on the vocal mechanism. The effects of psychological stresses common to young adulthood, such as educational commitments and early career choices, must also be understood. Upper respiratory infection and allergies are common in this age group. Treatment of these conditions must be tailored in the professional voice user because of the potential side effects of some medications and the performance imperatives of the patient. Surgical indications for tonsillectomy in the young voice patient are discussed. There are no special considerations in the evaluation and treatment of laryngeal pathology in the young adult, with the exception of limiting the use of sedative anesthesia. However, conservatism in surgical decision-making is advised. The development of a stable, efficient vocal technique and a mature professional background requires time, patience, and hard work.     

Effects of Family Therapy on Children''s Voices

The families of nine children with deviant voice qualities were selected for family treatment according to the SYGESTI model. Recordings of the children's speech were made before and after therapy. Perceptual evaluation of their voice quality showed significant improvement in various perceptual parameters after the therapy. Acoustical analysis confirmed changes of voice quality and mean fundamental frequency in speech. The therapy also was found to improve relations between family members, conflict management and other aspects of communication. The results suggest that these children's deviant voices were related to family conditions.     

The Effectiveness of Group Therapy for Students With Mild Voice Disorders: A Controlled Clinical Trial

Previous studies of students studying to be teachers have indicated that these students commonly have voice disorders. Ideally, voice disorders should be treated before students start their work as teachers, but the resources for this treatment are often limited. This study examines whether group voice therapy is effective for teacher students. Accordingly, 20 teacher students with mild voice disorders received group voice therapy (in three small groups), whereas 20 students with similar voice disorders served as a control group and consequently did not receive voice therapy. Two out of three outcome measures (perceptual evaluation of voice quality and a questionnaire on the occurrence of vocal symptoms) indicated significant changes in the treatment group compared with the control group. No differences between groups were noted in the laryngeal status. The results suggest that group voice therapy seems to be an effective method to treat students with mild voice disorders.     

Restraining mechanisms in regulating glottal closure during phonation

Recent experimental studies showed that isotropic vocal fold models were often blown wide apart and thus not able to maintain adductory position, resulting in voice production with noticeable breathy quality. This study showed that the capability of the vocal fold to resist deformation against airflow and maintain adductory position can be improved by stiffening the body-layer stiffness or increasing the anterior-posterior tension of the vocal folds, which presumably can be achieved through the contraction of the thyroarytenoid (TA) and cricothyroid (CT) muscles, respectively. Experiments in both physical models and excised larynges showed that, when these restraining mechanisms were activated, the vocal folds were better able to maintain effective adduction, resulting in voice production with much clearer quality and reduced breathiness. In humans, one or more restraining mechanisms may be activated at different levels to accommodate the varying degree of restraining required under different voice conditions.     

pH Dependence of the Au–CN Species Adsorbed onto Activated Carbon

Adsorption from aqueous solution of KAu(CN)₂ onto activated carbon at low pH is shown to produce a mixture of Au(CN)₂ ^– and AuCN. The relative concentrations can be altered by aging, drying and heating and are reversible to some extent. The bonding strength also alters considerably during these changes.     

Detection of high-frequency energy changes in sustained vowels produced by singers

The human voice spectrum above 5 kHz receives little attention. However, there are reasons to believe that this high-frequency energy (HFE) may play a role in perceived quality of voice in singing and speech. To fulfill this role, differences in HFE must first be detectable. To determine human ability to detect differences in HFE, the levels of the 8- and 16-kHz center-frequency octave bands were individually attenuated in sustained vowel sounds produced by singers and presented to listeners. Relatively small changes in HFE were in fact detectable, suggesting that this frequency range potentially contributes to the perception of especially the singing voice. Detection ability was greater in the 8-kHz octave than in the 16-kHz octave and varied with band energy level.     

Pharmacological agents that improve botulinum toxin efficacy in the treatment of spasmodic dysphonia

Botulinum toxin (botox) injection into the thyroarytenoid (TA) muscle is currently the most favored treatment for spasmodic dysphonia. However, results are often inconsistent. The purpose of this study was to identify a fast-acting neuromuscular blocking agent that could mimic botox effects to screen patients for therapy while still in the clinic. If the agent was noninteractive, it could also be injected coincidentally with botox and the resulting changes in voice used to predict the delayed effects due to botox. Evoked electromyography responses were recorded from the TA muscle in animal experiments to determine the time course for neuromuscular depression by botox and three fast-acting blocking agents: lidocaine, tubocurarine, and succinylcholine. Tubocurarine and succinylcholine proved to be suitable screening or predictor agents of botox efficacy, since they were reversible and mimicked botox action. In contrast, lidocaine produced irreversible effects.     

Vocal tract changes caused by phonation into a tube: a case study using computer tomography and finite-element modeling

Phonation into a glass tube is a voice training and therapy method that leads to beneficial effects in voice production. It has not been known, however, what changes occur in the vocal tract during and after the phonation into a tube. This pilot study examined the vocal tract shape in a female subject before, during, and after phonation into a tube using computer tomography (CT). Three-dimensional finite-element models (FEMs) of the vocal tract were derived from the CT images and used to study changes in vocal tract input impedance. When phonating on vowel [a:] the data showed tightened velopharyngeal closure and enlarged cross-sectional areas of the oropharyngeal and oral cavities during and after the tube-phonation. FEM calculations revealed an increased input inertance of the vocal tract and an increased acoustic energy radiated out of the vocal tract after the tube-phonation. The results indicate that the phonation into a tube causes changes in the vocal tract which remain also when the tube is removed. These effects may help improving voice production in patients and voice professionals.     

Wavelet transform modulus maxima based fractal correlation analysis

We study the intermittent behavior of the energy decay and the linear magnetic response of a glassy system during isothermal aging after a deep thermal quench, using the Edward-Anderson spin glass model as a paradigmatic example. The large intermittent changes in the two observables occur in a correlated fashion and through irreversible bursts, `quakes', which punctuate reversible and equilibrium-like fluctuations of zero average. The temporal distribution of the quakes is a Poisson distribution with an average growing logarithmically on time, indicating that the quakes are triggered by record sized fluctuations. As the drift of an aging system is to a good approximation subordinated to the quakes, simple analytical expressions [Sibani et al. Phys Rev B 74, 224407 (2006)] are available for the time and age dependence of the average response and average energy. These expressions are shown to capture the time dependencies of the EA simulation results. Finally, we argue that whenever the changes of the linear response function and of its conjugate autocorrelation function follow from the same intermittent events a fluctuation-dissipation-like relation can arise between the two in off-equilibrium aging.