Objective frequency-specific hearing thresholds definition for medicolegal purposes in case of occupational NIHL: ASSR outperforms CERA.

Audiological use of the 40 Hz-ASSR (auditory steady state responses) could be valuable for objectively estimating the frequency-specific threshold in adults undergoing an expertise examination for medicolegal and/or compensation purposes. The present prospective study was set up to clarify the relationship between the thresholds obtained by cortical evoked response audiometry (CERA) and by 40 Hz-ASSR, in the same ears, within a large homogeneous sample of 164 subjects (328 ears) with NIHL and well documented exposure to noise. All these subjects claimed financial compensation for occupational NIHL, and there was a suspicion of exaggeration of the reported NIHLs. ASSR thresholds show a good correlation with the CERA thresholds. However, a systematic shift is noticed, ASSR thresholds being on average (1-2 - 3 kHz) 4.38 dB lower (i.e. showing less hearing loss) than CERA thresholds. Moreover, the binaural multiple ASSR technique allows a considerable time gain when compared to the CERA.

The comparison of auditory behavioral and evoked potential responses (steady state and cortical) in subjects with occupational noise-induced hearing loss.

OBJECTIVE: To define difference scores between PTA, ASSR and CERA thresholds in subjects with occupational NIHL. DESIGN: 44 subjects undergoing a medico-legal expert assessment for occupational NIHL and fulfilling criteria of reliability were considered. Assessment included: PTA, 40 Hz binaural multiple ASSR and CERA (1-2-3 kHz). RESULTS: The respective average difference scores (ASSR - PTA) for 1, 2 and 3 kHz are 13.01 (SD 10.19) dB, 12.72 (SD 8.81) dB and 10.38 (SD 8.19) dB. The average (CERA - ASSR) difference scores are 1.25 (SD 14.63) dB for 1 kHz (NS), 2.73 (SD 13.03) dB for 2 kHz (NS) and 4.51 (SD 12.18) dB for 3 kHz. The correlation between PTA and ASSR (0.82) is significantly stronger than that between PTA and CERA (0.71). In a given subject, PTA thresholds are nearly always lower (i.e., better) than ASSR thresholds, whatever the frequency (1-2-3 kHz) and the side (right - left). A significant negative correlation is found between the difference score (ASSR - PTA) and the degree of hearing loss. CONCLUSION: ASSR outperforms CERA in a medicolegal context, although overestimating the behavioral thresholds by 10-13 dB.

Smartphones Offer New Opportunities in Clinical Voice Research.

Smartphone technology provides new opportunities for recording standardized voice samples of patients and sending the files by e-mail to the voice laboratory. This drastically improves the collection of baseline data, as used in research on efficiency of voice treatments. However, the basic requirement is the suitability of smartphones for recording and digitizing pathologic voices (mainly characterized by period perturbations and noise) without significant distortion. In this experiment, two smartphones (a very inexpensive one and a high-level one) were tested and compared with direct microphone recordings in a soundproof room. The voice stimuli consisted in synthesized deviant voice samples (median of fundamental frequency: 120 and 200 Hz) with three levels of jitter and three levels of added noise. All voice samples were analyzed using PRAAT software. The results show high correlations between jitter, shimmer, and noise-to-harmonics ratio measured on the recordings via both smartphones, the microphone, and measured directly on the sound files from the synthesizer. Smartphones thus appear adequate for reliable recording and digitizing of pathologic voices.

Tridimensional assessment of adductor spasmodic dysphonia pre- and post-treatment with Botulinum toxin.

Spasmodic dysphonia voices form, in the same way as substitution voices, a particular category of dysphonia that seems not suited for a standardized basic multidimensional assessment protocol, like the one proposed by the European Laryngological Society. Thirty-three exhaustive analyses were performed on voices of 19 patients diagnosed with adductor spasmodic dysphonia (SD), before and after treatment with Botulinum toxin. The speech material consisted of 40 short sentences phonetically selected for constant voicing. Seven perceptual parameters (traditional and dedicated) were blindly rated by a panel of experienced clinicians. Nine acoustic measures (mainly based on voicing evidence and periodicity) were achieved by a special analysis program suited for strongly irregular signals and validated with synthesized deviant voices. Patients also filled in a VHI-questionnaire. Significant improvement is shown by all three approaches. The traditional GRB perceptual parameters appear to be adequate for these patients. Conversely, the special acoustic analysis program is successful in objectivating the improved regularity of vocal fold vibration: the basic jitter remains the most valuable parameter, when reliably quantified. The VHI is well suited for the voice-related quality of life. Nevertheless, when considering pre-therapy and post-therapy changes, the current study illustrates a complete lack of correlation between the perceptual, acoustic, and self-assessment dimensions. Assessment of SD-voices needs to be tridimensional.

Voicing quantification is more relevant than period perturbation in substitution voices: an advanced acoustical study.

Quality of substitution voicing-i.e., phonation with a voice that is not generated by the vibration of two vocal folds-cannot be adequately evaluated with routinely used software for acoustic voice analysis that is aimed at 'common' dysphonias and nearly periodic voice signals. The AMPEX analysis program (Van Immerseel and Martens) has been shown previously to be able to detect periodicity in irregular signals with background noise, and to be suited for running speech. The validity of this analysis program is first tested using realistic synthesized voice signals with known levels of cycle-to-cycle perturbations and additive noise. Second, exhaustive acoustic analysis is performed of the voices of 116 patients surgically treated for advanced laryngeal cancer and recorded in seven European academic centers. All of them read out a short phonetically balanced passage. Patients were divided into six groups according to the oscillating structures they used to phonate. Results show that features related to quantification of voicing enable a distinction between the different groups, while the features reporting F(0)-instability fail to do so. Acoustic evaluation of voice quality in substitution voices thus best relies upon voicing quantification.

Differential effects of voice therapies on neurovegetative symptoms and complaints.

In previous studies, female patients in all age categories with a nonorganic dysphonia were found to report significantly more autonomic symptoms and complaints than healthy controls. After voice therapy, there was a highly significant reduction in the amount of autonomic symptoms and complaints (related or not related to voice). The present prospective study with a matched control group is designed to test the hypothesis that a specific kind of therapy is more efficient than the usual approaches in reducing these neurovegetative symptoms and complaints. Two matched groups of 34 patients diagnosed with nonorganic dysphonia and referred for voice therapy answered a questionnaire of 46 questions with 3 subsets and a consistency control. They received either "coordination therapy" (CTh)--a holistic approach addressing functional, personal and emotional aspects--or a conventional voice therapy (approximately 15 sessions). All patients again filled in a similar questionnaire after approximately 6 months. After therapy, there is in general a highly significant reduction in the amount of autonomic symptoms and complaints (related or not related to voice), to such an extent that patients report on average no more general neurovegetative symptoms and complaints than those of healthy controls. Symptoms and complaints of other nature (validity control) are not influenced. When compared with patients receiving conventional therapy, those who received CTh demonstrate a significantly higher reduction for the subset "neurovegetative symptoms/complaints related to voice and speech."

Possible mechanisms and gene involvement in speech problems in the 22q11.2 deletion syndrome.

SUMMARY: The 22q11.2 deletion syndrome represents a contiguous gene syndrome with a highly variable phenotype. To date, over 180 clinical features have been described. Studies have been done in order to identify the responsible genes. Several candidate genes such as TBX1 and COMT seem to be important in the development of the phenotype. One of the prevalent and serious problems encountered by patients with the 22q11.2 deletion is difficulty with speech. This may be due to a number of factors such as adenoid hypoplasia, muscle hypotonia, platybasia, upper airway asymmetry, and neuroanatomical abnormalities. The complex interaction of these factors leads to less favourable results after surgery to correct velopharyngeal insufficiency. This article offers a theoretical overview and proposes future research to investigate which factors are indeed responsible for the speech problems encountered by patients with the 22q11.2 deletion and identify responsible genes.

Neurovegetative symptoms and complaints before and after voice therapy for nonorganic habitual dysphonia.

In a previous study, female patients in all age categories with a nonorganic dysphonia were found to report significantly more autonomic symptoms and complaints than healthy controls. This could not be confirmed for the male subgroup. The present study is to corroborate and nuance this observation by investigating larger groups, and to determine if, after voice therapy, the number of autonomic symptoms and complaints-particularly those ones that have no obvious relation to voice function-decreases. It is a prospective study with a matched control group; 184 patients with nonorganic dysphonia and 126 normal controls answered a questionnaire of 46 questions with 3 subsets and a consistency control. One hundred and one patients received functional voice therapy and completed the questionnaire before and after treatment. A matched control group of 42 normal subjects also filled in the questionnaire two times, with an interval of about 6 months. Neurovegetative symptoms and complaints-voice related and not related-are reported in highly significant excess by patients (especially but not exclusively females) with habitual nonorganic voice disorder. After therapy, there is a highly significant reduction in the number of autonomic symptoms and complaints (related or not related to voice), to such an extent that patients report on average no more general neurovegetative symptoms and complaints than healthy controls (even less). The number of neurovegetative symptoms and complaints connected with voice function is also strongly reduced in patients after therapy, but remains in significant excess when compared with controls.

Prevalence of OME is reduced in young children using chewing gum.

OBJECTIVE: The present study investigates a possible relationship between use of chewing gum and otitis media with effusion (OME) in children. Chewing obviously activates jaw movements, increases salivary flow, and, by the way, the rate of swallowing and the rate of activations of peritubal muscles and tubal openings. Chewing also requires nasal respiration, thus preventing mouth breathing. DESIGN: Cross-sectional study: 1756 children (2 to 6 yr of age), apparently in good health and visiting different Dutch child health centers in the region of Utrecht were examined between September 1999 and April 2002. OME was diagnosed by combined tympanometry and otoscopy. The criterion for OME was unilateral or bilateral type B tympanogram, according to Jerger. The parents had to fill out a questionnaire with a question pertaining to the chewing habits of their child. RESULTS: Logistic regression points out that age and season as well as chewing gum-consuming habits significantly influence the prevalence of OME. The strongest effects are age (OME becomes less frequent with age) and season (OME occurs less when climate is more favorable), but -- ceteris paribus -- a child consuming daily or at least weekly chewing gum shows significantly less chance for OME than a child who seldom consumes or consumes no chewing gum (p = 0.023). CONCLUSIONS: In the case of regular use of chewing gum, the probability of having OME in children is reduced by 40%. It seems plausible that children with immature oral motorics do not like chewing gum.

Phoniatric provision and training: current European perspectives.

Communication disorders represent a major and growing problem worldwide. In Europe, the specialty of phoniatrics has developed partly in response to this important issue. This article reviews training and workforce issues in phoniatrics and raises key questions and issues that need resolution in the future.

Perceptual evaluation of substitution voices: development and evaluation of the (I)INFVo rating scale.

Substitution voicing cannot be evaluated accurately by the GRBAS perceptual rating scale, and there is a need for a valuable alternative. Therefore, we developed and tried out a perceptual rating scale, consisting of five new parameters: impression, intelligibility, noise, fluency and voicing, each to be scored between 0 (very bad score) to 10 (very good score for a substitution voice). In analogy to the GRBAS scale, they are then converted to deviance scores ranging from 0 (similar to good substitution voicing) to 3 (very deviant from good substitution voicing). Inter-individual agreement measured in a set of 24 semi-professional jury members seemed to be moderate for all parameters. Mean figures of 0.52, 0.51, 0.46, 0.53 and 0.46 are obtained for the parameters impression, intelligibility, noise, fluency and voicing, respectively. Because a high correlation exists between the first two parameters (0.917) and relying on the correlation figures between the two "I"s and the other parameters (correlation values for "impression" vary from 0.79-0.86; values for "intelligibility" range from 0.74-0.83), we suggest to discard the parameter impression, which turns the actual IINFVo scale into INFVo. The proposed (I)INFVo perceptual rating scale seems promising for the assessment of substitution voicing. Eventual improvements and practical proposals are discussed.

[The voice evaluation protocol of the European Laryngological Society (ELS) -- first results of a multicenter study]. / Das Stimmdiagnostik-Protokoll der European Laryngological Society (ELS) -- erste Erfahrungen im Rahmen einer Multizenterstudie.

INTRODUCTION: A multidimensional protocol has been established by the ELS in order to reach better agreement and standardisation for functional assessment of pathologic voices. In order to evaluate the validity, practicability and applicability of this protocol the experiences of 6 european voice centres have been analysed in a retrospective study. MATERIAL AND METHODS: The ELS protocol comprises 5 dimensions: perceptual voice evaluation, videostroboscopy, acoustics, aerodynamics and subjective rating by the patient. Results obtained in 94 patients with benign voice disorders were evaluated retrospectively in a multicenter study. RESULTS: According to our results, the validity, practicability and applicability of the ELS protocol was largely satisfactory. This was true for all "common" voice disorders, but not for extreme voice alterations (e. g. spasmodic dysphonia, aphonia, substitution voices). The 5 dimension proofed to be not redundant and were able to selectively differentiate pre- post changes among various etiologies of voice disorders, various types of treatment and genders.

Functional tubal therapy for persistent otitis media with effusion in children: myth or evidence?

Otitis media with effusion (OME), a form of inflammatory middle ear disease, is a common reason for young children to visit their family doctor and to have surgery. Tubal dysfunction plays a major role in the pathogenesis. In case of persistent OME, there seems to be a logical rationale for a favourable effect on the tubal dysfunction of a functional active motoric approach combined with behavioral changes (hygiene), and as a consequence for a therapeutic effect on the middle ear disease. The basic principles of this functional treatment are: active ventilation of the middle ear, correction of immature and undesirable deviant mouth habits, increasing swallowing frequency, activating jaw and palate movements, and encouraging the use of chewing gum. The bases for this functional therapy are critically analysed, and it may be concluded that all of these principles rely upon evidence based physiological mechanisms. However, the limited available clinical data from the literature are reviewed, and appear as methodologically weak. The results of an own prospective randomized pilot study comparing functional treatment with watchful waiting may be considered encouraging, since a borderline significance level was reached with a small amount of subjects.

Documentation of progress in voice therapy: perceptual, acoustic, and laryngostroboscopic findings pretherapy and posttherapy.

The effect of voice therapy in a group of chronically dysphonic patients with diverse diagnoses was studied according to the normal clinical procedure. The results were evaluated by perceptual rating, acoustic analysis, and the assessment of laryngostroboscopic recordings. Although the group effects for the differences between posttherapy and pretherapy data were clearly significant, the effects of voice therapy for the individual patients were divergent. For each of the three evaluation methods, a significant improvement was found for about 40% to 50% of the patients. The diversity of the therapy outcome among the patients could not be explained by the pretherapy status nor by age, gender, or diagnosis groups. In general, the perceptual ratings and the acoustic parameters from the baseline data were clearly correlated. However, these characterizations of the voice were only moderately correlated with the visual evaluation of the vocal fold vibrations. Relations among the three evaluation tools for the changes caused by voice therapy were very weak. The low correlation among the three methods suggests that a multidimensional evaluation of the voice is necessary to give a complete picture of the therapy outcome.

Self-assessment of voice therapy for chronic dysphonia.

The effects of voice therapy in a group of chronically dysphonic patients are determined using two quality-of-life (QOL) instruments: the Voice Handicap Index (VHI), and a simple three-item outcome scale (three visual analogue scales). Both instruments measure changes in the quality of the voice itself and in the extent of impairment resulting from the dysphonia as experienced by the patient in social and occupational settings. Statistical tests conducted on pre- and post-treatment data indicated significant improvements on both instruments for the group as a whole. At the individual level, however, the effects were diverse. For roughly 50% of the subjects, a significant improvement could be established. The positive changes as measured with the three-item scale were greater than those measured with the VHI. The results suggest that the two QOL instruments measure slightly different aspects of the subjective perception of the therapy effects. In order to obtain a general evaluation of the patient's handicap, it may suffice to ask some simple questions.

Implementation of the European Laryngological Society (ELS) basic protocol for assessing voice treatment effect.

OBJECTIVES: 93 patients with various kinds of organic benign voice pathology (vocal fold nodules, polyp, Reinke's oedema, unilateral paralysis, sulcus/scar) and/or with muscle tension dysphonia, were evaluated before and after their voice treatment (phonosurgery with voice therapy, antireflux medication, or voice therapy alone) in order to check the clinical relevance of a basic multidimensional protocol for assessing functional results of voice treatments, as developed by the Committee on Phoniatrics of the ELS. MATERIAL AND METHOD: The protocol has been used in different university voice clinics. It comprises 5 dimensions: Perception: Grade, Breathiness and Roughness from the GRBAS-scale, rated by two experienced judges: a phoniatrician/laryngologist and a speech therapist. Acoustics: Jitter % and Shimmer % computed on a /a:/, at comfortable loudness and pitch. Also Fo-range and softest possible intensity. Videostroboscopy: Glottal closure, regularity, mucosal wave and symmetry, rated separately. Phonation quotient: computed by dividing the vital capacity (ml) by the maximum phonation time (s) (best value of 2x3 trials). Self rating by the patient: voice quality in itself and general social/occupational handicap due to the voice problem rated separately. RESULTS: Results show that, at group level, the overall effects for each parameter indicate a significant improvement after treatment. However, the correlations between the pre/post changes for the different parameters are weak (low redundancy). CONCLUSION: The assessment of voice pathology needs to be multidimensional, as these multidimensional informations about voice changes lead to a better understanding of the actual way in which a treatment works.

Efficacy of voice therapy assessed with the Voice Range Profile (Phonetogram).

INTRODUCTION: Voice Range Profile (VRP), or Phonetography, is a widely used method of acoustic voice assessment: it explores and documents the extreme possibilities or capabilities of the voice by producing a chart displaying the intensity dynamics as a function of the fundamental frequency range. OBJECTIVES: In the present study VRP is used for investigating the efficacy of (isolated) functional voice therapy, and for defining the best suited VRP criteria for this purpose. MATERIAL AND METHOD: 30 adult voice patients with complaints of chronic dysphonia (> 4 months) fitted the acceptance--and exclusion criteria, and received functional voice therapy for 2 sessions/week during 3-6 months therapy (2x/week). VRP was performed before and after therapy, and a follow-up VRP was conducted 3 months after completion of the therapy. RESULTS: The parameters "softest intensity" and "VRP--area" seem the most sensitive parameters: they show an average highly significant improvement after therapy, and still an average significant improvement between the end of treatment and the follow-up measurement. CONCLUSION: For daily practice, an index (3 points-index) combining Fo-range and softest intensity is proposed.

Plasticity of voice quality: a prognostic factor for outcome of voice therapy?

Plasticity of voice quality is defined here as the degree of improvement in deviant voice quality that can be achieved immediately or quasi-immediately by changing basic voicing conditions, posture, articulation or resonance, breathing mechanics, laryngeal position, or auditory feedback. Thirty-two adult patients with various benign organic voice pathologies, and who had a (preoperative) functional voice therapy, were scored before therapy using a weighted multidimensional Index of Voice Plasticity (IVP). The hypothesis is that IVP could be a predictor of the final outcome of functional voice therapy, and therefore a correlation with a comparable quantification of the actual results of the therapy was investigated. The IVP shows a satisfactory correlation (Spearman's rho = 0.68) with the efficacy of (preoperative) voice therapy. The IVP also significantly differs between diagnostic categories. Although its predictive value remains limited, the Index of Voice Plasticity seems helpful in decision making for indication of (presurgical) voice therapy.

Laryngeal mucosa elasticity and viscosity in high and low relative air humidity.

In earlier work we showed that low relative humidity (RH) of inhaled air causes acoustic voice parameters such as jitter and shimmer to deteriorate. Other authors have shown negative effects on vocal efficiency. To explain these changes in the mechanical properties of the vocal folds, the effects of changes in RH of the air passing over microdissected mucosa of sheep larynges were studied. The dissected surface of the tissue specimen just touched Ringer solution and air of varying RH was blown over the specimen. The mucosa specimen was subjected to sinusoidal oscillations of length (strain) and the resulting force (stress) was measured. The gain and phase angle between the imposed strain and resulting stress were measured, and elasticity and viscosity were calculated. Two different air conditions were tested: air with high RH (100%) vs air with low RH (0%). Viscosity and stiffness increased significantly in both ambient conditions (P < 0.01). Dry dehydrating air resulted in a stiffer and more viscous cover than humid air (P < 0.001). These changes in mechanical characteristics may contribute to the effects on voice parameters described in earlier work.

A new method for measuring mechanical properties of laryngeal mucosa.

A study of the effect of exogenous hazardous agents or conditions on the mechanical characteristics of vocal fold mucosa should meet three methodological criteria. 1) The outer surface of the mucosa should be exposed to the agent or condition while the inner surface is exposed to a physiological environment. 2) Even slight changes in mechanical characteristics should be detected. 3) The applied strain should be within physiological ranges. To date, no such method has been described in the literature. A method meeting the listed criteria is proposed and evaluated here.