Peter Watson

University of Minnesota | UMN · Department of Speech-Language-Hearing Sciences

Background Laryngeal dystonia is a task-specific focal dystonia of laryngeal muscles that impairs speech and voice production. At present, there is no cure for LD. The most common therapeutic option for patients with LD involves Botulinum neurotoxin injections. Objective Provide empirical evidence that non-invasive vibro-tactile stimulation (VTS)...

Spasmodic dysphonia (SD) is an incurable focal dystonia of the larynx that impairs speech and communication. Vibro-tactile stimulation (VTS) alters afferent proprioceptive input to sensorimotor cortex that controls speech. This proof-of-concept study examined the effect of laryngeal VTS on speech quality and cortical activity in 13 SD participants...

Objective: Spasmodic dysphonia (SD) is a debilitating voice/speech disorder without an effective cure. To obtain a better understanding of the underlying cortical neural mechanism of the disease we analyzed electroencephalographic (EEG) signals of people with SD during voice production. Method: Ten SD individuals and 10 healthy volunteers produced...

Little is known about speech-related sensory systems and the link to speech in Parkinson's disease (PD). This study investigates auditory and somatosensory acuity and their association to speech in PD, using /s/ and /ʃ/ as speech targets. Ten adults with mild PD and ten age- and gender-matched healthy participants performed three tasks. In the audi...

We know very little about how muscles and motor units in one region of the upper airway are impacted by adjustments in an adjacent airway region. In this case, the focus is on regulation of the expiratory airstream by the larynx and how changes in laryngeal aperture impact muscle motor unit activities downstream in the pharynx. We selected sound pr...

INTRODUCTION. Speech impairments in persons with Parkinson’s disease (PD) are not solely accounted for by motor impairment. Somatosensory deficits were suggested associated with movement abnormalities of the trunk and limbs, but less is known about speech-related sensory systems in PD and their link to parkinsonian speech characteristics. This stud...

Measuring speech intelligibility is important in assessing the severity of impaired communication; and is used to demonstrate change overtime, e.g. before and after therapy. Orthographic transcription of speech is considered the clinical-gold standard of assessment, but can be time consuming. Many clinicians opt for quicker, subjective scaling such...

Focal dystonia of the head and neck are associated with a loss of kinesthetic acuity at muscles distant from the dystonic sites. That is, while the motor deficits in focal dystonia are confined, the associated somatosensory deficits are generalized. This is the first systematic study to examine, if patients diagnosed with spasmodic dystonia (SD) sh...

Parkinson’s disease (PD) presents with both sensory and motor deficits including speech, characterized by soft voice, monotonicity, and imprecise articulation. Both audition and somatosense are believed important for accurate speech production. Individual studies have identified auditory impairment and somatosensory impairment of the orofacial stru...

Formant transitions represent dynamic articulation processes and are useful to describe differences of articulation (e.g., normal and disordered speakers). Our method, considers the formant frequency change over time as a vector. We first reduce this vector to a single value which is plotted multi-dimensional space. Each dimension represents a data...

No PDF available ABSTRACT Watson, Ciccia, and Weismer (2003) described the relationship of initiating speech at different lung volumes to selected acoustic variables related to vowel production. It was found that some variables, such as dB SPL were related to a ‘direct' mechanical interaction with the breathing system. They also found that a variab...

There is an abundance of previous electromyographic (EMG) research conducted in the human tongue that has as its focus the extrinsic tongue muscle, genioglossus (GG) and its role in preserving upper airway patency for purposes of gas exchange. Comparatively few studies have documented GG EMG activities in the performance of volitional tasks such as...

Kent and Rosenbek [(1989)] hypothesized that abnormally high nasal resonance (HNRS) due to a paretic or paralyzed velopharyngeal mechanism in speakers with dysarthria could worsen intelligibility. Contrastingly, Whitehill?s [(2000)] review of literature found few that believe that HNRS associated with cleft palate contributes very little to a worse...

Most synthesis of nasal resonance is implemented by means of a parametric synthesizer [Klatt & Klatt, (1990)], offering a high degree of control, but having machine‐generated quality [Zraik et al., (2000)]. Typically this method is used to synthesize only small speech segments (i.e., sustained vowels and syllables; generating sentence‐long samples...

Deep‐brain stimulation (DBS) has been used for approximately 1 decade to ameliorate the symptoms of Parkinson's disease (PD). DBS often ameliorates many of the atypical motor symptoms of PD—with the exception of speech production. Clinically significant improvement of speech is not realized or in some cases is worsened [Tornquist et al. (2005). One...

Adaptive learning of speech behavior has been demonstrated in the areas of vowel height and backness [Houde (1998); Guenther (2006)] and pitch [Larson (1998)]. In each of these studies, the acoustic feedback presented to a speaker was perturbed, and most speakers modified their speech behavior to compensate. Adaptive learning is distinguished from...

Previous studies have documented that speech with flattened or inverted fundamental frequency (F0) contours is less intelligible than speech with natural variations in F0. The purpose of this present study was to further investigate how F0 manipulations affect speech intelligibility in background noise. Speech recognition in noise was measured for...

The advent of deep brain stimulation (DBS) has been an important advance in the treatment of Parkinson's disease (PD). DBS may be employed in the management of medication-refractory tremor or treatment-related motor complications, and may benefit between 4.5% and 20% of patients at some stage of their disease course. In Australia, patients with PD...

Purpose The purpose of this study was to offer a better understanding of the development of neuromotor control for speech breathing and provide a normative data set that can serve as a useful standard for clinical evaluation and management of young children with speech disorders involving the breathing subsystem. Method Speech breathing was studie...

Purpose This study examined the effect of fundamental frequency (F0) variation on the intelligibility of speech in an alaryngeal talker who used an electrolarynx (EL). Method One experienced alaryngeal talker produced variable F0 and a constant F0 with his EL as he read sentences aloud. As a control, a group of sentences with variable F0 was flatt...

Hird and Kirsner [K. Hird and K. Kirsner, Brain Lang., 80, 536-555 (2002)] reported that F0 is reset at higher values at the beginning of grammatically complete sentences during spontaneous speech. Hird and Kirsner reported that inspirations taken at the beginning of complete sentences "appeared" to be deep, but they did not make physiological meas...

Fitzsimons et al. [M. Fitzsimons, N. Sheahan, and H. Staunton, Brain Lang. 78, 94-108 (2001)] reported differences in the production of intonation between men and women during speech production. A relationship between the production and perception of segmental variables has been recognized [J. Perkell et al., Speech Commun. 22, 227-250 (1997)]; how...

Hypernasality in velocardiofacial syndrome (VCFS) is more severe, persistent, and difficult to manage compared to other populations with cleft palate or velopharyngeal (VP) dysfunction. This pilot study investigated why children with VCFS have more severe hypernasality. Pressure-flow methodology indirectly measured VP orifice size and VP closure ti...

Lexical factors (i.e., word frequency and phonological neighborhood density) influence speech perception and production. It is unknown if these factors are affected by Parkinson's disease (PD). Ten men with PD and ten healthy men read CVC words (varying orthogonally for word frequency and density) aloud while audio recorded. Acoustic analysis was p...

Purpose To examine the effect of fundamental frequency (F0) on the intelligibility of speech with flattened F0 contours in noise. Method Participants listened to sentences produced by 2 female talkers in white noise. The listening conditions included the unmodified original sentences and sentences with resynthesized F0 that reflected the average l...

Our purpose was to measure the change in quality of life (QoL) following deep brain stimulation of the globus pallidus interna (GPi-DBS) in advanced Parkinson 's disease (PD), and identifies any associations with changes in motor features of the disease. Eleven patients (age range 54-69 years, 2 women) underwent GPi-DBS (4 unilateral, 7 bilateral)....

Previous research has shown a difference in vowel acoustics between older and younger adults, possibly related to age-related changes in vocal tract morphology. Data suggest that vowel acoustics may vary as a function of neighborhood density and word frequency in older adults, possibly due to the mediating influence of lexical access. However, no s...

This investigation was motivated by observations that when persons with dysarthria increase loudness their speech improves. Some studies have indicated that this improvement may be related to an increase of prosodic variation. Studies have reported an increase of fundamental frequency (F0) variation with increased loudness, but there has been no ex...

Microelectrode recordings of human sensori-motor subthalamic neuronal activity during spoken sentence and syllable-repetition tasks provided an opportunity to evaluate the relationship between changes in neuronal activities and specific aspects of these vocal behaviors. Observed patterns of neuronal activity included a build up of activity in antic...

Laures and Weismer [JSLHR, 42, 1148 (1999)] reported that speech with natural variation in fundamental frequency (F0) is more intelligible in noise than speech with a flattened F0 contour. Cognitive-linguistic based explanations have been offered to account for this drop in intelligibility for the flattened condition, but a lower-level mechanism re...

Recently, the contribution of fundamental frequency (F0) variation to speech intelligibility in background noise has been studied [J. Laures and G. Weismer, JSLHR 42, 1148–1156 (1999)]. The process used for this analysis is to flatten the frequency contour at the average F0. Results show that sentences with flattened F0 are less intelligible than t...

Recent work has shown that neighborhood density (ND) affects vowel production in young adults (B. Munson and N. Solomon, J. Speech. Lang. Hear. Res. 47, 1048-1058 [2004]). Vowels in words with high ND were produced with larger F1/F2 acoustic vowel space; this effect was independent of word frequency and duration. This may reflect speakers' modifica...

Audio recordings were made while six vocally untrained individuals read sentences aloud after breathing to three different lung volume levels-typical, high, and low. A perceptual experiment was conducted on these speech samples. The perceptual experiment consisted of a two-alternative forced-choice design, in which listeners heard matched pairs of...

This study examined the relationship of speech breathing to other elements of speech production. It was hypothesized that initiating speech from different lung volumes would have an effect on different elements of the acoustic output. It was postulated that effects may be brought about by mechanical interaction as well as a dispersion of effort to...

Abdominal trussing constitutes an inward fixation of the abdominal wall. In the context of speech habilitation/rehabilitation, it is sometimes used to supplant, in part, the function of a paralyzed or paretic abdominal wall. A paralyzed or paretic abdominal wall may be found in individuals with cervical spinal cord injury or in individuals with oth...

Vocalization and breathing were studied in 40 healthy young children, including 5 boys and 5 girls at each, of ages of 18, 24, 30, and 36 months. A variable inductance plethysmograph was used to obtain estimates of volume changes of the rib cage, abdomen, and lung, as well as estimates of selected temporal features of the breathing cycle. Results i...

Vocalization and breathing were studied in 40 healthy infants, including five boys and five girls each at ages 5 weeks, 2.5 months, 6.5 months, and 12 months. Breathing was monitored through the use of a variable inductance plethysmograph that enabled estimates of the volume changes of the rib cage, abdomen, and lung, as well as estimates of select...

Respiratory function during speaking and singing was investigated in six male professional country singers. Function was studied using magnetometers to transduce anteroposterior diameter changes of the rib cage and abdomen while subjects performed various respiratory maneuvers, speaking activities, and singing activities. Results indicated that res...

This investigation examined the influence of cognitive-linguistic processing demands on speech breathing. Twenty women were studied during performance of two speaking tasks that were designed to differ in cognitive-linguistic planning requirements. Speech breathing was monitored with respiratory magnetometers from which recordings were made of the...

This investigation was designed to determine if velopharyngeal function during speech production, as reflected in measures of nasal air flow, differs with age in adults. Eighty subjects were studied, 40 women and 40 men, representing four age groups (20–30, 40–50, 60–70, and 80+ years). Results showed no age-related differences in nasal air flow. S...

Singing presents special control tasks for the respiratory apparatus. These tasks are performed variously by singers and have been studied through the use of several technologies. This paper will discuss data gathered over the past decade in this laboratory on the nature of respiratory function during singing and interpret those data in terms of co...

Established procedures for making chest wall kinematic observations (Hoit & Hixon, 1987) and pressure-flow observations (Smitheran & Hixon, 1981) were used to study respiratory and laryngeal function during whispering and speaking in 10 healthy young adults. Results indicate that whispering involves generally lower lung volumes, lower tracheal pres...

Kinematic behavior of the respiratory apparatus was studied during speaking and singing in four female subjects, all classical singers. Results revealed that respiratory events were similar to those observed previously for male classical singers. Findings suggest that respiratory function in classical singing is not sex-related in its kinematic man...

An investigation was conducted to elucidate the nature of speech breathing in children and adolescents and to determine if sex and age influence performance. Eighty healthy boys and girls representing four age groups (7, 10, 13, and 16 years) were studied using helium dilution to obtain measures of subdivisions of the lung volume and using magnetom...

Electromyography was used to investigate abdominal muscle activity during singing in four subjects, all of whom were trained classical singers. Results revealed regional differences in abdominal activation during the expiratory side of the breathing cycle. These were characterized by high-amplitude activity in the lateral region and low-amplitude a...

This study attempted to shed further light on the nature of prephonatory chest wall posturing by means of an investigation of the relative volume changes of the rib cage and abdomen during such posturing in normal young adult men and women. A new form of relative-volume chart was devised that enabled graphic display of the data in terms of selected...

Anteroposterior diameter changes of the rib cage and abdomen were recorded during respiratory and speaking activities in four adult subjects, three men and one woman, all of whom had extensive dramatic training and experience and were earning their livelihood as professional actors. Data were charted to solve for lung volume, and volume displacemen...

Anteroposterior diameter changes of the rib cage and abdomen were recorded during respiratory, speaking, and singing activities in six adult male subjects, all baritones with extensive classical singing training and performance experience. Data were charted to solve for lung volume, volume displacements of the rib cage and abdomen, and inferred mus...