Stephen M. Tasko

Psychological correlates of functional dysphonia:An investigation using the Minnesota multiphasic personality inventory

Abnormal psychological factors have been implicated in the development of functional dysphonia (FD). This investigation describes the personality and psychological characteristics of 25 female subjects who had received the diagnosis of FD. In all subjects symptoms were resolved after voice therapy. While vocally asymptomatic, these remitted subjects with FD completed the Minnesota Multiphasic Personality Inventory (MMPI), an objective personality questionnaire. When compared with a medical outpatient control group, the results showed that subjects with FD scored significantly higher on 7 of 10 clinical scales, suggesting an elevated degree of emotional maladjustment. A stepwise logistic discriminant analysis identified 2 clinical scales that provided valuable discriminatory power between the two groups. Scale 1 (Hs-hypochondriasis), which measures the number and type of reported somatic complaints, and scale 7 (Pt-psychasthenia), a measure of diffuse anxiety, discriminated the groups with 88% sensitivity and 89% specificity. The results suggested that in spite of symptom improvement after voice therapy, the subjects with FD continued to exhibit poor levels of adaptive functioning, which may represent trait-like vulnerability. The clinical implications of these results for voice practitioners are discussed.

Association of orofacial with laryngeal and respiratory motor output during speech

Speech motor coordination most likely involves synaptic coupling among neural systems that innervate orofacial, laryngeal, and respiratory muscles. The nature and strength of coupling of the orofacial with the respiratory and laryngeal systems was studied indirectly by correlating orofacial speeds with fundamental frequency, vocal intensity, and inspiratory volume during speech. Fourteen adult subjects repeated a simple test utterance at varying rates and vocal intensities while recordings were obtained of the acoustic signal and movements of the upper lip, lower lip, tongue, jaw, rib cage, and abdomen. Across subjects and orofacial speed measures (14 subjects × 4 structures), significant correlations were obtained for fundamental frequency in 42 of 56 cases, for intensity in 35 of 56 cases, and for inspiratory volume in 14 of 56 cases. These results suggest that during speech production there is significant neural coupling of orofacial muscle systems with the laryngeal and respiratory systems as they are involved in vocalization. Comparisons across the four orofacial structures revealed higher correlations for the jaw relative to other orofacial structures. This suggests stronger connectivity between neural systems linking the jaw with the laryngeal and respiratory systems. This finding may be relevant to the frame/content theory of speech production, which suggests that the neural circuitry involved in jaw motor control for speech has evolved to form relatively strong linkages with systems involved in vocalization.

Variability in tongue movement kinematics during normal liquid swallowing.

This study sought to develop a quantitative kinematic description of tongue movement for liquid swallowing in a group of 12 healthy subjects. X-ray microbeam technology was used to track the positions of six small pellets attached to the tongue and jaw while subjects swallowed water at 2- and 10-mL bolus volumes. A feature common to all subjects was a prominent rostral movement of the dorsal region of the tongue. In addition, all subjects consistently increased the displacement and maximum speed of this tongue movement with increased bolus volume. However, detailed movement analysis showed a variety of tongue movement patterns for the group. This variability across subjects was large enough that it was surprisingly difficult to provide a low-dimension quantitative description of the tongue kinematics during liquid swallowing.

Speed–curvature relations for speech-related articulatory movement

Abstract During speech production, oral articulator points exhibit spatially complex trajectories. This spatial complexity is partially reflected in the trajectorys curvature history (where curvature is defined as the rate of change of direction, parameterized for arc length). Informal observation of articulatory movement reveals that an increase in the degree of trajectory curvature is often associated with a slowing of the articulator. Such a relation between the speed and curvature of movement has been quantified for a variety of behaviors within the limb and oculomotor systems. This relation has been called the 1/3 power law. Such an association has not been quantified for speech movements. If speech movements adhere to the 1/3 power law, it would imply a specific constraint on the variability in spatial complexity (as reflected by curvature) and the time course of speech-related movements. This study empirically evaluated the relationship between articulator speed and trajectory curvature for speech-related mid-sagittal planar movements of the tongue, lower lip and mandible in a group of healthy speakers. Results revealed that movement speed and trajectory curvature are related by a power function whose exponent is near, but not exactly 1/3. Articulators exhibited systematic variations in the strength of association, and value of the exponent. These results suggest that speed and curvature of speech movement covary in ways similar to other motor systems.

Acoustic reflexes are common but not pervasive: evidence from the National Health and Nutrition Examination Survey, 1999–2012

Abstract Objective: To determine whether acoustic reflexes are pervasive (i.e. sufficiently prevalent to provide 95% confidence of at least 95% prevalence) and might be invoked in damage-risk criteria (DRC) and health hazard assessments (HHA) for impulsive noise. Design: Cross-sectional analyses of a nationally-representative study. Study sample: National Health and Nutrition Examination Survey (NHANES) data collected between 1999 and 2012 were used. Over 60 thousand reflex traces obtained from 15,106 NHANES participants were used in the study, along with demographic, audiometric, health and exposure variables obtained in that study. Results: Acoustic reflexes were not sufficiently prevalent to be deemed pervasive by any detection method or in any subgroup defined by age or audiometric characteristics. The odds of observing acoustic reflexes were greater for women, young adults, and people with better hearing sensitivity. Abnormally high tympanometric admittance and “Other” race/ethnicity (i.e. people who do not self-identify as exclusively Non-Hispanic White, Non-Hispanic Black, Mexican–American, or Hispanic) were associated with lower odds. Conclusions: Acoustic reflexes are not sufficiently prevalent to be included in DRC and HHA for impulsive noise.

Prevention of Noise-Induced Hearing Loss from Recreational Firearms

In the United States and other parts of the world, recreational firearm shooting is a popular sport that puts the hearing of the shooter at risk. Peak sound pressure levels (SPLs) from firearms range from ∼140 to 175 dB. The majority of recreational firearms (excluding small-caliber 0.17 and 0.22 rifles and air rifles) generate between 150 and 165 dB peak SPLs. High-intensity impulse sounds will permanently damage delicate cochlear structures, and thus individuals who shoot firearms are at a higher risk of bilateral, high-frequency, noise-induced hearing loss (NIHL) than peer groups who do not shoot. In this article, we describe several factors that influence the risk of NIHL including the use of a muzzle brake, the number of shots fired, the distance between shooters, the shooting environment, the choice of ammunition, the use of a suppressor, and hearing protection fit and use. Prevention strategies that address these factors and recommendations for specialized hearing protectors designed for shooting sports are offered. Partnerships are needed between the hearing health community, shooting sport groups, and wildlife conservation organizations to develop and disseminate accurate information and promote organizational resources that support hearing loss prevention efforts.

The reduction of gunshot noise and auditory risk through the use of firearm suppressors

Law enforcement, security, and military personnel train with small-caliber firearms that present a significant risk of noise induced hearing loss for the operator and range instructors. Measurements of three rifles and one pistol equipped with suppressors were conducted at an outdoor firing range using subsonic and supersonic ammunition. Suppressed and unsuppressed recordings were analyzed. Microphones were located to the left of the muzzle, to the right and left of the shooter’s head, and one meter behind the shooter’s head at the nominal instructor’s position. Recordings were collected with a National Instruments PXI 1082 chassis with an NI 4499 data acquisition board at a 200 kHz sampling rate. Analysis of the peak sound pressure levels (dB SPL) and 8-h equivalent A-weighted energy (LAeq8) were conducted. The suppressors reduced the peak between 15 and 25 dB SPL and the LAeq8 between 8 and 28 dB. Reduced noise levels at the source will reduce auditory risk but do not necessarily eliminate the need for ...

Auditory risk of air rifles

Abstract Objective: To characterize the impulse noise exposure and auditory risk for air rifle users for both youth and adults. Design: Acoustic characteristics were examined and the auditory risk estimates were evaluated using contemporary damage-risk criteria for unprotected adult listeners and the 120-dB peak limit and LAeq75 exposure limit suggested by the World Health Organization (1999) for children. Study sample: Impulses were generated by nine pellet air rifles and one BB air rifle. Results: None of the air rifles generated peak levels that exceeded the 140 dB peak limit for adults, and eight (80%) exceeded the 120 dB peak SPL limit for youth. In general, for both adults and youth, there is minimal auditory risk when shooting fewer than 100 unprotected shots with pellet air rifles. Air rifles with suppressors were less hazardous than those without suppressors, and the pellet air rifles with higher velocities were generally more hazardous than those with lower velocities. Conclusion: To minimize auditory risk, youth should utilize air rifles with an integrated suppressor and lower velocity ratings. Air rifle shooters are advised to wear hearing protection whenever engaging in shooting activities in order to gain self-efficacy and model appropriate hearing health behaviors necessary for recreational firearm use.

Prevalence of acoustic reflexes in the United States

The acoustic reflex is a contraction of the middle ear muscles in response to high-level sounds. Acoustic reflexes are invoked as a protective mechanism in some damage-risk criteria (DRC). However, acoustic reflexes are not always observed among people without auditory dysfunction, and should not be included in DRC unless there is 95% certainty that 95% of the population have acoustic reflexes. In the current study, we present the prevalence of acoustic reflexes among people 12 years and older (N > 11,400), using data from the National Health and Nutrition Examination Survey (NHANES). The NHANES can be used to produce prevalence estimates generalizable to the non-institutionalized U.S. population. Ipsilateral reflexes were screened at two elicitor frequencies and detected using Frequentist methods and via Kalman filtering of the reflex trace. Reflexes are pervasive only among those with hearing thresholds better than 15 dB HL at all frequencies, and fall below the criterion certainty with poorer sensitivity even at lower frequencies. Age and tympanometric variables are also related to reflex detection. Reflex prevalence is generally high among young people with adequate hearing sensitivity for unrestricted military duty, but the prevalence is not uniform among audiometric configurations within this hearing profile.

Kinematic factors underlying timing in connected speech

Current understanding of the kinematic factors underlying speech timing has been largely derived from short, simple speech tasks such as citation words. However, timing analyses based upon acoustic segment durations have shown that timing rules differ for citation words and connected speech. Thus it is not clear how well temporal correlates of citation‐style speech movement might generalize to connected speech. A better understanding of the articulatory bases of timing patterns associated with connected speech may aid in the refinement of natural‐sounding articulatory‐based speech synthesis. This study sought to determine temporal correlates of articulator fleshpoint movements in orally read speech recorded from 20 normal adult speakers of American English. Position histories associated with the tongue blade, tongue dorsum, jaw, and lower lip were segmented into series of movement strokes, and measures of distance, maximum speed, and duration were determined for each stroke. Canonical correlation analysis...