Effects of postlingual deafness on speech production: implications for the role of auditory feedback

This study investigated some effects of postlingual deafness on speech by exploring selected properties of consonants, vowels, and suprasegmentals in the speech of seven totally, postlingually deafened individuals. The observed speech properties included parameters that function as phonological contrasts in English, as well as parameters that constitute primarily phonetic distinctions. The results demonstrated that postlingual deafness affects the production of all classes of speech sounds, suggesting that auditory feedback is implicated in regulating the phonetic precision of consonants, vowels, and suprasegmentals over the long term. In addition, the results are discussed in relation to factors that may influence the degree of speech impairment, such as age at onset of deafness.

Acoustic analysis of experimental prosthetic apparatus on spatial distribution formants

This study concerns the effects of various prosthetic apparatus on speech perception. In this study we analyzed not only the first and second formant frequencies (as have often been studied previously) but also the third formant frequencies, and the three formant frequencies en masse. Our study demonstrated that of the six kinds of prosthetic apparatus we examined, the least effective apparatus was the L.S. type, while the most effective was the M.P. type.

Integrating perceptual and instrumental procedures in the assessment of velopharyngeal insufficiency

Although technology for the instrumental assessment of velopharyngeal function has advanced, management decisions still too often depend only on subjective perceptual analyses. Both perceptual and instrumental appraisal are necessary for adequate assessment. Instrumental assessment is essential prior to surgical or other long-term management. The assessment is only as valid as the instruments used. If such instruments are not readily available, clinicians should refer patients to centers where they are available and these examinations are routinely performed.

Palatopharyngeal activity in cleft palate subjects

A literature review of the nature of the musculature of the cleft palate and the pharynx is provided and a rationale presented for determining the anatomic level at which muscle activity occurs. Nasal endoscopy with a rigid telescope and the placement of miniaturized pressure transducers against the pharyngeal walls were the techniques used to investigate palatopharyngeal defects in cleft palate subjects. Ten basic patterns of palatopharyngeal movement are described and the likely interplay of the various muscles in producing these complex movements is discussed. Closure patterns of the palatopharyngeal isthmus varied according to whether the subjects were speaking, sucking, or swallowing. It was concluded that the presence of an obturator in the pharynx affects the pattern of activity and that the obturator should be developed to speech function rather than to swallowing.

Speech characteristics as indicators of depressive illness

Measures of the rate of change of voice fundamental frequency, fundamental frequency variability, reading and counting times, and different measures of pause time were compared in 28 depressed patients and 13 healthy controls. The fundamental frequency variables were lower in the depressed group, and the pauses between the interviewer's questions and the patient's answers were longer. The remaining speech variables, including the summed duration of interdigit pauses in counting from 1 to 10 (speech pause time), did not differ between the groups.

Coarticulation effects on the nasalization of vowels using nasal/voice amplitude ratio instrumentation

Nasal coarticulation in phonetically controlled nonsense syllables was investigated in four normal adult speakers. Nasalization was determined using the ratio of a nasal accelerometer signal amplitude to airborn microphone signal amplitude. Measurements of nasalization were made at the midpoint of vowels and at a constant time from the nasal consonant. Nasal acoustical coupling was greater for high vowels than for low vowels in all consonant contexts. Nasalization was also greater for vowels between two nasal consonants than for vowels between a nasal consonant and a fricative or stop. Results for progressive versus regressive assimilation depended on the measurement strategy. For within-vowel measurements made a constant time from the nasal consonant, prenasal vowels showed greater nasalization than postnasal vowels. This nasal accelerometric technique shows promise for clinical assessment of articulatory details of velar function.

The Velotrace: a device for monitoring velar position

This paper describes the Velotrace, a mechanical device designed to allow the collection of analog data on velar position. The device consists of two levers connected through a push rod and carried on a pair of thin supports rods. The device is positioned in the nasal passage with the internal lever resting on the nasal surface of the velum and the external lever positioned outside the nose. The movements of the external lever reflect the movement of the internal lever as it follows velar movement and are recorded as an analog signal using an optoelectronic position-sensing system. Results of evaluation studies indicate that the Velotrace accurately reflects the relatively rapid movements of the velum during speech.

Soft-talker: a sound level monitor for the hard-of-hearing using an improved tactile transducer

We describe a small wearable device which enables deaf people to monitor the volume of their voices; it consists of a microphone, amplifier, signal rectifier, smoothing and a level detector connected to a wrist-worn vibrator, and provides vibrotactile feedback of voice level.

A digital sound editor

A series of digital computer programs which facilitate the production and control of acoustic stimuli for hearing assessment and research are described. The package, which is available for PDP 11 computers under RT-11, allows sounds to be digitized, adjusted for amplitude and/or dc offset, edited while in digital form, and output to file or tape. The waveform editor package includes facilities to edit sounds in time--with some sections removed or added with temporal precision of 0.1 msec or better. Two or more sounds may also be combined for stereo or monaural (sound-on-sound) output, or two may be concatenated. Together, the programs permit a wide range of manipulations useful in preparing sound stimuli for use in hearing experiments or in clinical audiometry.

Pressure measurements during speech production using semiconductor miniature pressure transducers: impact on models for speech production

It appears that temperature instabilities are a major obstacle hindering the use of semiconductor strain gauge pressure transducers in speech research, especially when absolute pressure data are mandatory. In this paper a simple and reliable method for an in vivo calibration of this kind of transducer is described. The most important error source, the drift of the zero pressure level due to temperature changes, is discussed, and an estimation of the measurement accuracy which can be obtained is given. Moreover, some registrations of subglottal, supraglottal, and transglottal pressure are presented. It is shown that the pressure recordings allow us to obtain estimates of the volume flow in the trachea and pharynx. Analysis of those waveforms appears to lead to new insights into the physical processes underlying voice production. Specifically, an independent glottal contribution to the skewing of the glottal flow pulses is identified.

Speech technology: present and future applications in the airborne environment

Advanced speech technology systems, specifically voice recognition and voice synthesis systems are being considered as viable solutions to the problem of distributing pilot workload in today's increasingly complex airborne environment. The U.S. Air Force has funded various projects in this area over the past few years including studies defining and establishing priorities for candidate tasks to be accomplished by voice control, as well as a developmental hardware program which entered a flight test phase in December 1982. The applications of this technology are constrained only by the rate of its evolution. Certain tasks have already been identified as excellent candidates for control by a voice system and the present hardware is capable of being configured to perform these tasks. Other tasks have been identified as potential candidates. Although these candidates are tasks which would impact pilot workload, present technology is incapable fo supporting them.

Functionally specific articulatory cooperation following jaw perturbations during speech: evidence for coordinative structures

In three experiments we show that articulatory patterns in response to jaw perturbations are specific to the utterance produced. In Experiments 1 and 2, an unexpected constant force load (5.88 N) applied during upward jaw motion for final /b/ closure in the utterance /baeb/ revealed nearly immediate compensation in upper and lower lips, but not the tongue, on the first perturbation trial. The same perturbation applied during the utterance /baez/ evoked rapid and increased tongue-muscle activity for /z/ frication, but no active lip compensation. Although jaw perturbation represented a threat to both utterances, no perceptible distortion of speech occurred. In Experiment 3, the phase of the jaw perturbation was varied during the production of bilabial consonants. Remote reactions in the upper lip were observed only when the jaw was perturbed during the closing phase of motion. These findings provide evidence for flexibly assembled coordinative structures in speech production.

Auditory and visual feedback of nasalization using a modified accelerometric method

A method of providing auditory and visual feedback of nasalization to hypernasal speakers using the Horii Oral-Nasal Coupling (HONC) technique is described. This noninvasive method appears promising as an evaluative as well as a rehabilitative tool in dealing with speakers with nasal resonance problems.

An accelerometric measure as a physical correlate of perceived hypernasality in speech

This study investigated the correlation between a physical measure of oral-nasal coupling and perceived hypernasality in speech. A modified accelerometric method was utilized to extract distributional characteristics of a ratio of the nasal accelerometric amplitude to the voice amplitude during simulated hypernasal reading by 11 female talkers. Perceived hypernasality scores for the readings were derived from a panel of 30 listeners in a paired-comparison paradigm. A correlation coefficient of .92 was obtained between the mean nasal-to-voice ratio and the perceived hypernasality scores. The results indicated that the nasal-to-voice amplitude ratio is a promising index of perceived hypernasality in speech.

Toward the automated measurement of the type-A behavior pattern

Sixty-six structured interviews that were rated by Rosenman on a 5-point Type A/B behavior pattern scale, were scored by means of a semi-automated system for verbosity, voice volume and the temporal pacing of speech. A significant negative correlation obtained between interviewees' A/B ratings and their reaction-time scores; significant positive correlations obtained between their behavior type ratings and their voice volume and duration of vocalization scores. A regression equation consisting of reaction-time and voice volume scores correctly classified the A/B ratings of 89 percent of the interviewees. The significant correlations that were obtained between the interviewer's and the interviewees' speech patterns emphasize the need for standardizing the interviewer's style. Finally, the findings suggest that anxiety-arousal is a mediating variable in the relationship between Type-A behavior and coronary heart disease.

Instrumentation and validity for direct-readout voice onset time measurement

Methods and instrumentation for direct readout of voice onset time (VOT) are presented along with sample measurements for three subjects. Mean VOT and intrasubject variability are compared with data obtained from wide-band spectrograms. The results suggest that the instrumentation described yields VOT values comparable to those obtained from wide-band spectrograms. Implications for diagnosis are discussed and research needs are identified.

[Computer aerography. Methodology and clinical use exemplified by labio-maxilla-palate clefts (author's transl)]

Computer aerography, which is based on the use of the double-aerometer by Sven Smith, is described as an objective method for clinic-scientific problems. Medical examination of labio-maxilla-palate-cleft patients shows how this procedure, which has a low degree of inconvenience and is also applicable to children, contributes essentially to the settling of clinic-scientific problems. Further scopes are still being tested.