Joan E. Sussman

Articulatory, developmental, and gender effects on measures of fundamental frequency and jitter.

Fundamental frequency (Fo) and jitter were measured in digitized live-voice productions of sustained vowels [a], [i], and [u] from women, men, and 6- through 9-year-old children. Results showed (a) significant developmental differences for mean Fo and for the pattern of jitter by vowel type, (b) significant gender differences in Fo and jitter only for adults, (c) significant differences in Fo and jitter according to vowel type for all subjects, and (d) similar amounts of mean absolute jitter for children and women for all vowels with nonsignificantly different values of jitter for boys and men on [i] and [u] productions. Results are related to Hondas theory of intrinsic Fo for vowels and to Titzes neurologic model of jitter.

Reliability of listener transcriptions of compensatory articulations.

OBJECTIVE This study examined the ability of speech-language pathologists to transcribe compensatory articulation errors. DESIGN Speech-language pathologists phonetically transcribed audiorecordings of 130 monosyllabic words, 70 of which contained compensatory articulations. PARTICIPANTS The participants for this study were two groups of 10 speech-language pathologists. Group I included speech-language pathologists who were experienced in evaluating children with cleft palate, and group II speech-language pathologists were not. RESULTS Marked variability was evident across listeners, with percentages of agreement ranging from 19 to 71 (mean agreement = 41%). The experienced listeners performed significantly better on the transcription task than the inexperienced listeners, but poor interjudge agreement was evident across both groups. CONCLUSIONS The results of this study suggest that speech-language pathologists may differ in their understanding of the auditory perceptual characteristics of compensatory articulations. The results underscore the need for increased training and standardization of transcription procedures.

Perceptual evaluation of Hypernasality compared to HONC measures: The role of experience

Objectives Nasality ratings from experienced and inexperienced listeners were compared to accelerometric measures using the Horii Oral Nasal Coupling (HONC) Index to determine if one groups ratings are more closely related to the HONC Index measures. The reliability of listener ratings was studied to determine if experienced listeners had better reliability than inexperienced listeners. The influence of phonetic content was analyzed to learn if ratings of sentences with stop consonants yielded higher correlations with HONC scores than sentences containing glides. Design Experienced and inexperienced listeners’ ratings of hypernasality were correlated to the HONC measures for two nonnasal sentence productions. Analysis of variance compared experienced versus inexperienced listener ratings. Participants Ten listeners who were speech-language pathologists with at least 10 years of experience in assessing hypernasality and 10 listeners who were graduate students in communicative disorders with less than 1 year of experience. Speech samples were acquired from 13 children with varying degrees of hypernasality and 5 children with normal nasality. Results Correlations between ratings of hypernasality and HONC scores were .60 for the experienced group and .52 for the inexperienced group. In general, the experienced listeners rated the hypernasality of the speakers as less severe. Both groups had similar intrajudge reliability. Hypernasality ratings were not influenced by sentence context. Conclusions Hypernasality can be rated in a reliable fashion regardless of listener experience. The correlations between the objective measure of nasalization (HONC) and the perceptual ratings were not as high as expected. Factors contributing to obtaining only moderate correlations will be discussed.

Impact of clear, loud, and slow speech on scaled intelligibility and speech severity in Parkinson's disease and multiple sclerosis.

PURPOSE The perceptual consequences of rate reduction, increased vocal intensity, and clear speech were studied in speakers with multiple sclerosis (MS), Parkinsons disease (PD), and healthy controls. METHOD Seventy-eight speakers read sentences in habitual, clear, loud, and slow conditions. Sentences were equated for peak amplitude and mixed with multitalker babble for presentation to listeners. Using a computerized visual analog scale, listeners judged intelligibility or speech severity as operationally defined in Sussman and Tjaden (2012). RESULTS Loud and clear but not slow conditions improved intelligibility relative to the habitual condition. With the exception of the loud condition for the PD group, speech severity did not improve above habitual and was reduced relative to habitual in some instances. Intelligibility and speech severity were strongly related, but relationships for disordered speakers were weaker in clear and slow conditions versus habitual. CONCLUSIONS Both clear and loud speech show promise for improving intelligibility and maintaining or improving speech severity in multitalker babble for speakers with mild dysarthria secondary to MS or PD, at least as these perceptual constructs were defined and measured in this study. Although scaled intelligibility and speech severity overlap, the metrics further appear to have some separate value in documenting treatment-related speech changes.

Increased vocal intensity due to the Lombard effect in speakers with Parkinson's disease: Simultaneous laryngeal and respiratory strategies

PURPOSE The objective of the present study was to investigate whether speakers with hypophonia, secondary to Parkinsons disease (PD), would increases their vocal intensity when speaking in a noisy environment (Lombard effect). The other objective was to examine the underlying laryngeal and respiratory strategies used to increase vocal intensity. METHODS Thirty-three participants with PD were included for study. Each participant was fitted with the SpeechVive™ device that played multi-talker babble noise into one ear during speech. Using acoustic, aerodynamic and respiratory kinematic techniques, the simultaneous laryngeal and respiratory mechanisms used to regulate vocal intensity were examined. RESULTS Significant group results showed that most speakers with PD (26/33) were successful at increasing their vocal intensity when speaking in the condition of multi-talker babble noise. They were able to support their increased vocal intensity and subglottal pressure with combined strategies from both the laryngeal and respiratory mechanisms. Individual speaker analysis indicated that the particular laryngeal and respiratory interactions differed among speakers. CONCLUSIONS The SpeechVive™ device elicited higher vocal intensities from patients with PD. Speakers used different combinations of laryngeal and respiratory physiologic mechanisms to increase vocal intensity, thus suggesting that disease process does not uniformly affect the speech subsystems. LEARNING OUTCOMES Readers will be able to: (1) identify speech characteristics of people with Parkinsons disease (PD), (2) identify typical respiratory strategies for increasing sound pressure level (SPL), (3) identify typical laryngeal strategies for increasing SPL, (4) define the Lombard effect.

Acoustic and perceptual consequences of clear and loud speech.

Objective: Several issues concerning F2 slope in dysarthria were addressed by obtaining speech acoustic measures and judgments of intelligibility for sentences produced in Habitual, Clear and Loud conditions by speakers with Parkinsons disease (PD) and healthy controls. Patients and Methods: Acoustic measures of average and maximum F2 slope for diphthongs, duration and intensity were obtained. Listeners judged intelligibility using a visual analog scale. Differences in measures among groups and conditions as well as relationships among measures were examined. Results: Average and maximum F2 slope metrics were strongly correlated, but only average F2 slope consistently differed among groups and conditions, with shallower slopes for the PD group and steeper slopes for Clear speech versus Habitual and Loud. Clear and Loud speech were also characterized by lengthened durations, increased intensity and improved intelligibility versus Habitual. F2 slope and intensity were unrelated, and F2 slope was a significant predictor of intelligibility. Conclusion: Average diphthong F2 slope was more sensitive than maximum F2 slope to articulatory mechanism involvement in mild dysarthria in PD. F2 slope holds promise as an objective measure of treatment-related changes in the articulatory mechanism for therapeutic techniques that focus on articulation.

The control of aerodynamics, acoustics, and perceptual characteristics during speech production

One of the most important areas of study in speech motor control is the identification of control variables, the variables controlled by the nervous system during motor tasks. The current study examined two hypotheses regarding control variables in speech production: (1) pressure and resistance in the vocal tract are controlled, and (2) perceptual and acoustic accuracy are controlled. Aerodynamic and acoustic data were collected on 20 subjects in three conditions, normally (NT), with an open air pressure bleed tube in place (TWB), and with a closed bleed tube in place (TNB). The voice recordings collected from the speakers in the production study were used in the perceptual study. Results showed that oral pressure (Po) was significantly lower in the TWB condition than in the NT and TNB conditions. The Po in the TWB condition seemed to be related to maintenance of subglottal pressure (Ps). Examination of the perceptual and acoustic data indicated that perceptual accuracy for [a] was achieved by maintaining Ps to preserve a steady sound pressure level, fundamental frequency, and voicing. Overall, it appeared speakers controlled pressure in compensating, but for the ultimate goal of maintaining acoustic and perceptual accuracy.

HONC Measures in 4- to 6-Year-Old Children

OBJECTIVE To collect normative data using Horiis Oral Nasal Coupling Index (HONC) from 4- to 6-year-old children without cleft palate to be used in the evaluation of young children with cleft palate. In addition, to determine whether HONC values in children are similar to those of adults and thus show that the HONC ratio successfully normalizes nasal accelerometric signals across age, gender, and vocal intensity. DESIGN Measurement of accelerometric and acoustic signals from novel nasal and nonnasal utterances, which the children repeated after the experimenter. Measurements also included four sustained [m] productions, which were used to calibrate correction factors used to equate nasal and oral signals during a sustained [m] production. SETTING Laboratory at a state university. PARTICIPANTS Ten girls and 10 boys, aged 4 to 6 years, with normal speech, language, and hearing. RESULTS Differences of 13 dB (HONC) were found to separate nasal from nonnasal sentences. No significant difference in HONC score was found across gender for nasal/nonnasal sentences and [m] productions. The correction factors generated during [m] calibration procedures did not differ between girls and boys. CONCLUSIONS Horii Oral Nasal Coupling Index differences between nasal and nonnasal utterances appear to be valid and reliable measures in both children and adults for detection of disorders of nasal resonance.

Functional Anatomy of the Masking Level Difference, an fMRI Study

Introduction Masking level differences (MLDs) are differences in the hearing threshold for the detection of a signal presented in a noise background, where either the phase of the signal or noise is reversed between ears. We use N0/Nπ to denote noise presented in-phase/out-of-phase between ears and S0/Sπ to denote a 500 Hz sine wave signal as in/out-of-phase. Signal detection level for the noise/signal combinations N0Sπ and NπS0 is typically 10–20 dB better than for N0S0. All combinations have the same spectrum, level, and duration of both the signal and the noise. Methods Ten participants (5 female), age: 22–43, with N0Sπ-N0S0 MLDs greater than 10 dB, were imaged using a sparse BOLD fMRI sequence, with a 9 second gap (1 second quiet preceding stimuli). Band-pass (400–600 Hz) noise and an enveloped signal (.25 second tone burst, 50% duty-cycle) were used to create the stimuli. Brain maps of statistically significant regions were formed from a second-level analysis using SPM5. Results The contrast NπS0- N0Sπ had significant regions of activation in the right pulvinar, corpus callosum, and insula bilaterally. The left inferior frontal gyrus had significant activation for contrasts N0Sπ-N0S0 and NπS0-N0S0. The contrast N0S0-N0Sπ revealed a region in the right insula, and the contrast N0S0-NπS0 had a region of significance in the left insula. Conclusion Our results extend the view that the thalamus acts as a gating mechanism to enable dichotic listening, and suggest that MLD processing is accomplished through thalamic communication with the insula, which communicate across the corpus callosum to either enhance or diminish the binaural signal (depending on the MLD condition). The audibility improvement of the signal with both MLD conditions is likely reflected by activation in the left inferior frontal gyrus, a late stage in the what/where model of auditory processing.

Multi-Site Phasic Neural Activity Mediates the Execution of An Auditory Continuous Performance Task: A PET and Electrophysiological Study

We studied an auditory continuous performance task with positron emission tomography (PET) and EEG‐derived current density reconstructions (CDRs) to define the spatial and temporal aspects of auditory attention.