G. Paul Moore lecture: Rational thought: The impact of voice science upon voice care

Recent evolution in scientific knowledge and technology has led to monumental improvement in the standard of care for patients with voice disorders. New concepts in anatomy, physiology, measurement, and analysis have provided voice care professionals with not merely better understanding, but moreover an extensive vocabulary with which to think about voice function and dysfunction. Previously, we had to depend too much upon anecdote and “the art of medicine.” Thanks to scientific advances, we now have the tools we need for rational thought about the human voice. This is the fundamental change responsible for recent great advances in voice care.     

The clinical voice laboratory: Clinical application of voice research

In the past decade the number of voice laboratories has increased dramatically. Their primary mission is to enhance patient care by the application of knowledge gained from basic research. They also are dedicated to further improvement of diagnostic and therapeutic resources. The strength of the voice laboratory lies in collaboration between the clinician and the scientist.     

Correlation of VHI-10 to Voice Laboratory Measurements Across Five Common Voice Disorders

ObjectiveTo correlate change in Voice Handicap Index (VHI)-10 scores with corresponding voice laboratory measures across five voice disorders.Study DesignRetrospective study.MethodsOne hundred fifty patients aged >18 years with primary diagnosis of vocal fold lesions, primary muscle tension dysphonia-1, atrophy, unilateral vocal fold paralysis (UVFP), and scar. For each group, participants with the largest change in VHI-10 between two periods (T_A and T_B) were selected. The dates of the VHI-10 values were linked to corresponding acoustic/aerodynamic and audio-perceptual measures. Change in voice laboratory values were analyzed for correlation with each other and with VHI-10.ResultsVHI-10 scores were greater for patients with UVFP than other disorders. The only disorder-specific correlation between voice laboratory measure and VHI-10 was average phonatory airflow in speech for patients with UVFP. Average airflow in repeated phonemes was strongly correlated with average airflow in speech (r = 0.75). Acoustic measures did not significantly change between time points.ConclusionsThe lack of correlations between the VHI-10 change scores and voice laboratory measures may be due to differing constructs of each measure; namely, handicap versus physiological function. Presuming corroboration between these measures may be faulty. Average airflow in speech may be the most ecologically valid measure for patients with UVFP. Although aerodynamic measures changed between the time points, acoustic measures did not. Correlations to VHI-10 and change between time points may be found with other acoustic measures.     

Common Practices of Voice Therapists in the Evaluation of Patients

This study surveys voice therapists regarding common diagnostic practices in patients referred for therapy with the diagnosis of muscle tension dysphonia (broadly defined as the "hyperfunctional" component of the dysphonia). Through postings on the e-mail list of the ASHA special interest division on voice, speech pathologists with at least 3 years' experience in stroboscopy and acoustic instrumentation were invited to complete the survey. Results from 53 completed surveys demonstrated that voice quality and patient self-perception are the sole assessments performed by all therapists. Voice quality, observation of body posture and movement, and probing the patient's ability to alter voice production are each significantly more likely to be performed than the more objective stroboscopic, acoustic, aerodynamic, and EGG assessments. Further, the tasks of defining specific therapy session goals and helping the patient to achieve a particular target skill are considered best served by measures of vocal quality, observation of body position and movement, and judging the patient's ability to alter voice production. For definition of the overall therapy goal, stroboscopy and patient perception scales are added to all of the subjective assessment measures as being important. Acoustic data are considered most important for patient reinforcement and outcomes assessment. Implications of these findings are discussed, and topics for further exploration are identified.     

The accent method of voice therapy: Effect of accentuations on FO, SPL, and airflow

The effect of the increased flow rate (ΔU) in response to the Accent Method exercises on fundamental frequency (FO) and sound pressure level (SPL) was studied in three subjects (professionally trained, trained, and untrained in this method). In all the subjects, the rhythmic accentuated exercises produced a variable degree of increase in FO (ΔFO) and SPL (ΔSPL). The professionally trained subject showed greater ΔFO and ΔSPL in response to the ΔU in the fastest tempo, which requires higher skills. Both trained subjects showed a greater correlation between ΔU and both ΔSPL and ΔFO, as well as between ΔFO and ΔSPL, as compared to the untrained subject. The effects of the accentuated exercises on FO and SPL in response to the increased airflow rate (ΔU) thus appear to demonstrate the treating effectiveness of the Accent Method.     

Voice field measurements—a new method of examination: the influence of hearing on the human voice

There are various methods to evaluate voice parameters. Original software was used to assess the voice quality by the staff of AUDIO-Fon centr Brno, Czech Republic. A group of hereditary deaf persons was examined. Deaf persons have all of the biological conditions to make voice except for the possibility of acoustic feedback. We examined the voices of 35 persons (20 men and 15 women) with hereditary profound hearing impairments, and we compared voice parameters with the voice of intact persons. To measure we used special software called voice field measurements (VFMs). The program graphically records voice frequency and intensity. VFM is an objective method that enables the assessment of basic physical voice characteristics. It is suitable for the examination of both intact and disturbed voice. The voice of the deaf has a higher basic voice frequency in men as well as in women. This type of voice production, ie, childlike voice, which is fixed only by a motor stereotype, is much more demanding for a mature larynx. Hearing influences both the voice development and speech production. The voice of persons with hearing impairments has a higher basic voice frequency regardless of their sex. This type of voice production, which is fixed only by a motor stereotype, ie, child voice, is much more demanding for a larynx of an adult. Thus, phonation of deaf people is more demanding and their voice production needs greater effort. Deaf people, despite an intact phonic apparatus, cannot produce more than one type of voice. They cannot modulate their voices concerning the frequency and dynamics. They cannot change their voices continually. The voice is limited in both of these parameters (frequency and dynamics). If a deaf person wants to change a voice characteristic, it is possible only by discontinuous changes-"skipping."     

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.     

On the terminology of voice research

This article reviews problems associated with establishment of a scientifically accurate, internationally recognized, multilingual terminology to describe voice. Two strategies for developing terminology are discussed: consensus and dictation. Ontological decisions are considered an integral part of developing terminology. We conclude that terminological problems should be solved by a terminological committee—as yet to be established—as they average from problems in interpreting the literature and the results of voice research. A comprehensive bibliography and audio tape of the multilingual terminology describing voice would help facilitate adaptation and understanding of the terms defined.