Elizabeth S. Heller Murray

The Relationship between Relative Fundamental Frequency and a Kinematic Estimate of Laryngeal Stiffness in Healthy Adults.

Purpose This study examined the relationship between the acoustic measure relative fundamental frequency (RFF) and a kinematic estimate of laryngeal stiffness. Method Twelve healthy adults (mean age = 22.7 years, SD = 4.4; 10 women, 2 men) produced repetitions of /ifi/ while varying their vocal effort during simultaneous acoustic and video nasendoscopic recordings. RFF was determined from the last 10 voicing cycles before the voiceless obstruent (RFF offset) and the first 10 cycles of revoicing (RFF onset). A kinematic stiffness ratio was calculated for the vocal fold adductory gesture during revoicing by normalizing the maximum angular velocity by the maximum glottic angle during the voiceless obstruent. Results A linear mixed effect model indicated that RFF offset and onset were significant predictors of the kinematic stiffness ratios. The model accounted for 52% of the variance in the kinematic data. Individual relationships between RFF and kinematic stiffness ratios varied across participants, with at least moderate negative correlations in 83% of participants for RFF offset but only 40% of participants for RFF onset. Conclusions RFF significantly predicted kinematic estimates of laryngeal stiffness in healthy speakers and has the potential to be a useful clinical indicator of laryngeal tension. Further research is needed in individuals with voice disorders.

Voice Relative Fundamental Frequency Via Neck-Skin Acceleration in Individuals With Voice Disorders

PURPOSE This study investigated the use of neck-skin acceleration for relative fundamental frequency (RFF) analysis. METHOD Forty individuals with voice disorders associated with vocal hyperfunction and 20 age- and sex-matched control participants were recorded with a subglottal neck-surface accelerometer and a microphone while producing speech stimuli appropriate for RFF. Rater reliabilities, RFF means, and RFF standard deviations derived from the accelerometer were compared with those derived from the microphone. RESULTS RFF estimated from the accelerometer had slightly higher intrarater reliability and identical interrater reliability compared with values estimated with the microphone. Although sensor type and the Vocal Cycle × Sensor and Vocal Cycle × Sensor × Group interactions showed significant effects on RFF means, the typical RFF pattern could be derived from either sensor. For both sensors, the RFF of individuals with vocal hyperfunction was lower than that of the controls. Sensor type and its interactions did not have significant effects on RFF standard deviations. CONCLUSIONS RFF can be reliably estimated using an accelerometer, but these values cannot be compared with those collected via microphone. Future studies are needed to determine the physiological basis of RFF and examine the effect of sensors on RFF in practical voice assessment and monitoring settings.

Relative Fundamental Frequency Distinguishes between Phonotraumatic and Non-Phonotraumatic Vocal Hyperfunction.

Purpose The purpose of this article is to examine the ability of an acoustic measure, relative fundamental frequency (RFF), to distinguish between two subtypes of vocal hyperfunction (VH): phonotraumatic (PVH) and non-phonotraumatic (NPVH). Method RFF values were compared among control individuals with typical voices (N = 49), individuals with PVH (N = 54), and individuals with NPVH (N = 35). Results Offset Cycle 10 RFF differed significantly among all 3 groups with values progressively decreasing for controls, individuals with NPVH, and individuals with PVH. Individuals with PVH also had lower Offset Cycles 8 and 9 relative to the other 2 groups and lower RFF values for Offset Cycle 7 relative to controls. There was also a trend for lower Onset Cycle 1 RFF values for the PVH group compared with the NPVH group. Conclusions RFF values were significantly different between controls and individuals with VH and also between the two subtypes of VH. This study adds further support to the notion that the differences between these two subsets of VH may be functional as well as structural.

Validation of an Algorithm for Semi-automated Estimation of Voice Relative Fundamental Frequency

Objectives: Relative fundamental frequency (RFF) has shown promise as an acoustic measure of voice, but the subjective and time-consuming nature of its manual estimation has made clinical translation infeasible. Here, a faster, more objective algorithm for RFF estimation is evaluated in a large and diverse sample of individuals with and without voice disorders. Methods: Acoustic recordings were collected from 154 individuals with voice disorders and 36 age- and sex-matched controls with typical voices. These recordings were split into training and 2 testing sets. Using an algorithm tuned to the training set, semi-automated RFF estimates in the testing sets were compared to manual RFF estimates derived from 3 trained technicians. Results: The semi-automated RFF estimations were highly correlated (r = 0.82-0.91) with the manual RFF estimates. Conclusions: Fast and more objective estimation of RFF makes large-scale RFF analysis feasible. This algorithm allows for future work to optimize RFF measures and expand their potential for clinical voice assessment.

Effects of Biofeedback on Control and Generalization of Nasalization in Typical Speakers

Purpose The purpose of this study was to determine the effects of biofeedback on control of nasalization in individuals with typical speech. Method Forty-eight individuals with typical speech attempted to increase and decrease vowel nasalization. During training, stimuli consisted of consonant-vowel-consonant (CVC) tokens with the center vowels /a/ or /i/ in either a nasal or nonnasal phonemic context (e.g., /mim/ vs. /bib/), depending on the participants training group. Half of the participants had access to augmentative visual feedback during training, which was based on a less-invasive acoustic, accelerometric measure of vowel nasalization-the Horii oral-nasal coupling (HONC) score. During pre- and posttraining assessments, acoustically based nasalance was also measured from the center vowels /a/, /i/, /æ/, and /u/ of CVCs in both nasal and nonnasal contexts. Results Linear regressions indicated that both phonemic contexts (nasal or nonnasal) and the presence of augmentative visual feedback during training were significant predictors for changes in nasalance scores from pre- to posttraining. Conclusions Participants were able to change the nasalization of their speech following a training period with HONC biofeedback. Future work is necessary to examine the effect of such training in individuals with velopharyngeal dysfunction.

The Impact of Glottal Configuration on Speech Breathing

OBJECTIVE The purpose of this study was to examine whether changes in respiratory patterns occurred in response to volitional changes in glottal configuration. METHODS Twelve vocally healthy participants read a passage while wearing the Inductotrace respiratory inductive plethysmograph, which measures the excursions of the rib cage and abdomen. Participants read the passage 5 times in a typical speaking voice (baseline phase), 10 times in an experimental voice, which was similar to a breathy vocal quality (experimental phase), and 5 times again in a typical speaking voice (return phase). Kinematic estimates of lung volume (LV) initiation, LV termination, and LV excursion were collected for each speech breath. RESULTS Participants spoke with larger LV excursions during the experimental phase, characterized by increased LV initiation and decreased LV termination compared with the baseline phase. CONCLUSION In response to volitional changes in glottal configuration, healthy individuals spoke with increased LV excursion. They both responded to changes (decreasing LV termination) and planned for more efficient future utterances (increasing LV initiation) during the experimental phase. This study demonstrated that respiratory patterns change in response to changes in glottal configuration; future work will examine these patterns in individuals with voice disorders.

Development of an Electronic Documentation System for Voice Therapy: A New Teaching and Clinical Research Tool

Although research on the outcomes of the treatment of voice disorders is widely discussed, there is a lack of information regarding the specifics of the methods and tasks undertaken during the therapy sessions. One reason may be a lack of a clear, standardized method of documentation for the voice therapy. Therefore this article discusses the development of a new electronic documentation system for voice therapy. The goals of this documentation system are to create a user-friendly, flexible system, which implements the standard terminology and structure proposed in the recent voice therapy taxonomy (Van Stan, Roy, Awan, Stemple, & Hillman, 2015). This documentation system stores all the information from the therapy session in a local database, which is accessible for analysis within or between patients. This allows large-scale datasets to be compiled for future clinical research. This documentation system includes definitions for all terminology, and includes hierarchies, which are not required, but can be followed for additional structure. This documentation system can be used as a teaching tool, with the ability to accommodate the needs of both the novice and expert clinician.

Acoustic and kinematic estimates of laryngeal stiffness

Vocal fold movements differ between individuals with typical voices and those with voice disorders associated with increased laryngeal stiffness. Modeling suggests that changes in vocal fold kinematics correspond to changes in laryngeal muscle stiffness. In this study, 12 healthy adults produced repetitions of /ifi/ while varying their self-perceived vocal effort during simultaneous acoustic and nasal-endoscopic recordings, in order to compare a kinematic estimate of laryngeal stiffness to an acoustic measure. The acoustic measure, relative fundamental frequency (RFF), was determined from the last ten voicing cycles before the voiceless obstruent (offset) and the first ten voicing cycles of the following vowel (onset). A kinematic stiffness ratio was calculated by normalizing the maximum angular velocity by the maximum value of the glottic angle during vocal fold adductory gestures. A linear mixed-effect model found that RFF accounted for 52% of the variance in the kinematic data. Examined within-subject,...