Estimating respiratory volumes from rib cage and abdominal displacements during ventilatory and speech activities.

This methodological study examined the predictive strength associated with modeling respiratory volumes from chest-wall movements during selected ventilatory and speech activities. A linearized magnetometry system transduced the anterior-posterior diameters of the rib cage and abdomen, supplying kinematic data that were used to estimate respiratory volumes. Kinematic and airflow measures were acquired during (a) tidal ventilation, (b) vital capacity maneuvers, (c) Rainbow Passage reading at customary loudness, (d) Rainbow Passage reading at twice-customary loudness, (e) extemporaneous speech, and (f) /a/ prolongation. Multiple-regression statistics were applied to the body surface and integrated airflow data to obtain (a) intercepts, (b) volume-motion coefficients for the rib cage and abdomen, and (c) coefficients of determination. Volumes estimated by applying regression-derived intercepts and volume-motion coefficients to the respiratory kinematic data were then compared to integrated airflow signals. Two magnetometer-based, volume-estimation strategies were contrasted for the speech tasks, one based on volume-motion coefficients derived from that particular speech activity and one based on volume-motion coefficients derived from tidal ventilation. Regression-derived intercepts and volume-motion coefficients for the abdomen varied significantly across subjects but not tasks. Volume-motion coefficients for the rib cage varied significantly across both subjects and tasks. Coefficients of determination for the magnetometer-based volume estimates were affected significantly by subjects and tasks but not by volume-estimation strategies. The calibration, use, and potential limitation of respiratory kinematic devices for speech research are discussed.

Acoustical effects of endotracheal intubation.

Certain acoustical consequences of endotracheal intubation were examined in 13 male cardiovascular-surgery patients. Each subject recorded three tokens of a sustained vowel 1 day before intubation, 1 day after, upon discharge, and during a follow-up visit. Eight acoustical measures were obtained from the audio-recorded vowels: (a) mean fundamental frequency (Fo), (b) Fo standard deviation, (c) Fo perturbation quotient, (d) mean sound pressure level (SPL), (e) SPL standard deviation, (f) SPL perturbation quotient, (g) spectral flatness of the residue signal, and (h) coefficient of excess. Mean Fo, Fo standard deviation, mean SPL, SPL standard deviation, and coefficient of excess did not differ significantly across recording sessions, although certain predictable trends were apparent. Fo perturbation quotient, SPL perturbation quotient, and spectral flatness of the residue signal varied significantly across sessions, implying that these acoustical measures may be useful in the identification and monitoring of even minor intubation-related laryngeal trauma.

Methodological variables affecting phonational frequency range in adults.

This study examined the effects of selected elicitation variables on phonational frequency (Fo) range in normal adults. Twenty men and 20 women responded to five audiotaped tone conditions: (a) discrete steps, (b) slow steps, (c) fast steps, (d) slow glissando, and (e) fast glissando. These stimuli were devised to elicit each person's maximal and minimal Fo. All elicitation conditions evoked a significantly higher maximal Fo and a significantly larger Fo range (in both hertz and semitones) than did the discrete-steps condition. Fast steps produced a significantly higher minimal Fo than did fast glissando. Both slow glissando and fast glissando yielded a significantly larger Fo range in semitones than did fast steps. Finally, the women demonstrated a significantly larger Fo range (in hertz but not semitones) than did the men.

Speech rate reduction and "nasality" in normal speakers.

This study explored the effects of reduced speech rate on nasal/voice accelerometric measures and nasality ratings. Nasal/voice accelerometric measures were obtained from normal adults for various speech stimuli and speaking rates. Stimuli included three sentences (one obstruent-loaded, one semivowel-loaded, and one containing a single nasal), and /pv/ syllable trains.. Speakers read the stimuli at their normal rate, half their normal rate, and as slowly as possible. In addition, a computer program paced each speaker at rates of 1, 2, and 3 syllables per second. The nasal/voice accelerometric values revealed significant stimulus effects but no rate effects. The nasality ratings of experienced listeners, evaluated as a function of stimulus and speaking rate, were compared to the accelerometric measures. The nasality scale values demonstrated small, but statistically significant, stimulus and rate effects. However, the nasality percepts were poorly correlated with the nasal/voice accelerometric measures.

Verbal fluency characteristics of normal and aphasic speakers.

Fourteen mildly aphasic and 14 normal speakers responded to an oral verbal fluency task for five different semantic categories. Retrieved words were scored within each 15-s time interval of a 60-s task as highly representative (i.e., having a high frequency of occurrence in a previous normative study), moderately representative (i.e., having a moderate frequency of occurrence), or highly unrepresentative (i.e., having a low frequency of occurrence). Both speaker groups were affected similarly by category type, and both retrieved words according to prior data-based notions of semantic categorical organization. The two groups differed with respect to the interaction between time intervals and representativeness levels. The different verbal fluency performance of the aphasic subjects was related to both the temporal occurrence of a word within a 60-s response interval and to its representativeness level (prototypicality) within a particular semantic category.

Factors influencing fundamental frequency range estimates in children.

Selected elicitation conditions were manipulated to determine their effect on fundamental frequency (Fo) range estimates in children. Forty normal children each responded to five autiotaped tone conditions: (a) discrete steps, (b) slow steps, (c) fast steps, (d) slow glissando, and (e) fast glissando. These tonal stimuli were devised to elicit each child's maximal and minimal Fo. The traditional discrete-steps condition was associated with a lower maximal Fo, higher minimal Fo, and a more restricted Fo range than all other conditions.

Surface EMG and related measures in normal and vocally hyperfunctional speakers.

Surface electromyographic (EMG) signals were detected from the laryngeal area of 7 normal and 7 vocally hyperfunctional speakers during rest, two resisted-force maneuvers, vowel production, and connected speech. Vowel fundamental frequency, absolute and relative period perturbation, laryngeal-palpation ratings, and harshness ratings were acquired as well. The two groups differed significantly on all EMG measures except those associated with the resisted-force maneuvers, the vowel EMG-to-rest EMG ratio, and the speech EMG-to-rest EMG ratio. Moderately high correlations were evident between selected clinical measures and speech EMG values.

Factors associated with dysphonia in high school cheerleaders.

Questionnaire responses that encompassed the severity of acute, cheering-related dysphonia, typical vocal use, vocal history, medical history, smoking and drinking behaviors, and A-Scale personality characteristics were obtained from 146 female high school cheerleaders. Multiple-regression analysis was chosen to examine the degree to which the dysphonia severity items could be associated with the remaining items. The results indicated that acute, cheering-related dysphonia may be preceded or accompanied by a compact set of clinical signs that could be incorporated easily into a screening protocol for prospective cheerleaders.

Relation between nasal/voice accelerometric values and interval estimates of hypernasality.

Nasal/throat accelerometric ratios were obtained from 12 hypernasal and three normal children. The accelerometric voltages comprising the ratio were analogs of nasal and anterior-neck tissue vibrations. Audio recordings, which were obtained simultaneously with the accelerometric voltages, were later judged for hypernasality using an equal-appearing-interval (EAI) scale. High correlations were evident between accelerometric and EAI values when a stimulus sentence contained obstruents, semivowels, and vowels. No correlation existed between accelerometric measures and hypernasality judgments when a sentence contained primarily nasal phonemes and vowels.

Correspondence between an accelerometric nasal/voice amplitude ratio and listeners' direct magnitude estimations of hypernasality.

Miniature accelerometers were used to transduce nasal and anterior-neck tissue vibrations of 12 hypernasal and 3 normal children. The accelerometric voltages provided an analog implementation of Horii's (1980) nasal/voice ratio. Simultaneous audio recordings were later evaluated for hypernasality by listeners. Listeners' direct magnitude estimations (DME) of hypernasality were highly correlated with the accelerometric nasal/voice ratio when the stimulus sentences contained obstruents, nonnasal semivowels, and vowels. No correlation existed between DME and accelerometric values when the stimulus sentences contained primarily nasal semivowels and vowels.

A cineradiographic study of chin marker positioning: implications for the strain gauge transduction of jaw movement.

Three normal adult subjects were filmed using lateral-view, high-speed cineradiography to measure the amount of movement of external skin points on the jaw relative to the underlying jaw bone. Metal markers were secured to the skin to simulate cantilever beam attachment points commonly utilized in the strain gauge transduction of jaw movements. Standard deviations of chin marker movement relative to the jaw ranged from 0.52 to 1.28 mm in an anterior-posterior direction and 0.67 to 2.31 mm in a superior-inferior direction. Lower lip and chin marker positions were highly correlated in the superior-inferior direction. Chin marker positions tended to be more superior and, in one subject, more anterior for labial than for nonlabial different contexts. The degree of variability was not systematically different for the two different contexts.

Effects of selected vocal disguises upon speaker identification by listening.

This research was designed to investigate the effects of selected vocal disguises upon speaker identification by listening. The experiment consisted of 360 pair discriminations presented in a fixed-sequence mode. The listeners were asked to decide whether two sentences were uttered by the same or different speakers and to rate their degree of confidence in each decision. The speakers produced two sentence sets utilizing their normal speaking mode and five selected disguises. One member of each stimulus pair in the listening task was always an undisguised speech sample; the other member was either disguised or undisguised. Two listener groups were trained for the task: a naive group of 24 undergraduate students, and a sophisticated group of three doctoral students and three professors of Speech and Hearing Sciences. Both groups of listeners were able to discriminate speakers with a moderately high degree of accuracy (92% correct) when both members of the stimulus pair were undisguised. The inclusion of a disguised speech sample in the stimulus pair significantly interfered with listener performance (59%--81% correct depending upon the particular disguise). These results present a similar pattern to this authors' previous results utilizing spectrographic speaker-identification tasks (Reich et al., 1976).

Teflon laryngoplasty: an acoustical and perceptual study.

A 61-year-old male with a 24-year history of unilateral vocal fold paralysis was evaluated by a speech-language pathologist and an otolaryngologist for 52 weeks following Teflon injection. Tape recordings of the patient's voice were obtained one week prior to and one, eight, 20, and 52 weeks subsequent to Teflon injection. The recorded samples were presented in the backward-play mode to a panel of speech-language pathology graduate students to obtain ratings of the degree of hoarseness, roughness, and pleasantness. Results of the perceptual aspect of this study revealed a general reduction in perceived hoarseness and an enhancement of perceived pleasantness following Teflon injection. Measurement of selected acoustic properties revealed a lowering of median fundamental frequency, a reduction of fundamental aperiodicity for isolated but not excerpted vowels, an elimination of certain frictional noise components, and an increase of certain harmonic components following Teflon injection.