Sound output of electronic laryngeal prostheses at room and body temperature

An electronic laryngeal prosthesis, fully-implantable in the neck, is a desirable source of artificial voice. Emitted sound energy in a frequency range suitable for adult males and females must be of the correct period and intensity and rich in powerful harmonics. Any such device places severe demands on a bioencapsulant used to enclose the transducer. Location of the devices within the central neck demands a prosthesis-coating combination capable of passing sound energy at central body temperature. This study reports on four identical prostheses, coated with a polyvinylidene chloride, a copolyether polyurethane, a semi-rigid epoxy, or uncoated. Units were tested at room (72 degrees F) and body (100 degrees F) temperature in a sound-isolated chamber. Results indicated that performance of the uncoated unit was altered due to temperature effects. The presence of the polymer encapsulants did not have any differential effect on sound spectrum due to temperature differences.

Interaction between articulatory movements and vocal pitch control in Japanese word accent

In order to investigate the interaction between articulatory and vocal pitch controls, EMGs of the cricothyroid (CT) and sternohyoid (SH) muscles were recorded during utterances of two-mora Japanese words with rising and falling accent types in the Tokyo dialects. The test words consisted of combinations of open and closed vowels. It was revealed that the changes in CT activity were consistently observed in correspondence with the F0 shift according to the accent types, while the SH muscle was observed to be active both for jaw opening and F0 lowering, with some subject-to-subject difference. It was also observed that the time lag between the decrease in CT activity and the F0 fall varied with a shift in the relative timing of SH activity in one subject, but not in the other. Articulatory jaw opening with SH activation was considered to positively contribute to F0 lowering, but the use of this mechanism appeared to be optional at least in the Tokyo accent.

On the variability in F0 patterning and the function of F0 timing in languages where pitch cues stress

The basic property of pitch as a cue to linguistic stress is fundamental frequency (F0) change. That leaves room for a lot of variation: in the direction of the change, the amount of change, and its exact coordination with the stressed syllable. Examples (from the literature) from a number of languages and dialects attest that they do indeed exhibit quite striking differences in the stress/F0 relationship. The decisiveness, under certain circumstances, of the timing of F0 events is illustrated by the results of a pilot experiment with a disyllabic Danish word: The location of a two-semitone rise from the first to the second syllable--before or after the intervocalic sonorant consonant--will shift listeners' location of the stress.

Textual aspects of prosody in Swedish

The present paper explores the textual function of intonation in indicating coherence and boundaries between successive utterances of speech. An informal listening test showed how such prosodic coupling can be used to mark coherence between sentences of a text unit. The coherence is expressed as a downdrift of F0 peaks and valleys characterizing the whole text unit. The boundary between two text units is signalled by terminating one and beginning another downdrift ramp. The characteristic features of the downdrift pattern seem to be (1) an adjustment of F0 values to the length of the text unit, and (2) an adaptation of the F0 of the beginning of a succeeding sentence to that of the later part of a preceding one in the same unit. Some preliminary implications of these results for speech planning are discussed.

Infant labial, apical and velar stop productions: a voice onset time analysis

Initial prevocalic labial, apical and velar stops, as produced by eight 9- to 12-month-old Swiss-German infants, were examined spectrographically for voice onset time (VOT). Results indicate that VOTs for each place of articulation cluster in the 0- to + 30-ms voicing lag range. Comparisons of the present infant data with available results from adult Swiss-German stop productions show the VOT distributions to be very similar. The present infant data for apical stops are also compared with available data from 122-month-old American-English and Lebanese-Arabic infants. Since all three infant populations show similar VOT distributions, one might conclude that the forces of nature rather than nurture determine manner of infant apical stop production.

Declination: construct or intrinsic feature of speech pitch?

Declination is taken as the focus of studying pitch phenomena from an acoustic, physiological and perceptual point of view. It is shown that originally declination was no more than a theoretical construct to account for the interpretation of acoustic F0 recordings. Recently, psycholinguistic considerations have enhanced the domain of application so as to account for this phenomenon. The literature is reviewed and the authors take issue over the various claims put forward by others, such as the dominance of the topline over the baseline approach, and the amount of pre-programming involved in declination, as manifested in its slope and in linguistically determined resetting.

F0 in the production of lenis and fortis plosives

The contribution of fundamental frequency (F0) to the distinction between lenis and fortis plosives is investigated for German in monotone, falling, and rising pitch patterns. A larger F0 drop is found in the stressed vowel before lenis, as against fortis, in disyllabic words with the contour high + fall. These F0 differences do not have aerodynamic causes due to articulatory constraints on phonation but can be related to an active laryngeal control in two production patterns differing in overall articulatory effort and also resulting in an articulatory timing contrast. Hypotheses are formulated as regards the importance of this F0 difference for perception, and with respect to the production and the perception of the lenis/fortis opposition along the F0 parameter in English.

Spectro-temporal characteristics of single units in the auditory midbrain of the lightly anaesthetised grass frog (Rana temporaria L) investigated with noise stimuli

About 30% of the auditory units in the midbrain of the lightly anaesthetised grass frog respond in a sustained way to stationary pseudorandom noise. This response is described by the spectro-temporal receptive field (STRF), the regions in the spectro-temporal domain where the average second-order functional of those parts of the stimulus ensemble that precede the action potentials differ from the average second-order functional of the stimulus ensemble. By means of the STRF frequency selectivity, postactivation suppression and lateral suppression can quantitatively be studied under one and the same experimental condition. Auditory units that respond to stationary noise are localised in those parts of the torus where fibres enter from the olivary nucleus. They are characterised by relatively short latencies to tones and probably represent the first information-processing stage in the torus semicircularis.

The cry characteristics of an infant who died of the sudden infant death syndrome

Fourteen cries of a four day old infant who subsequently died suddenly of unexplained causes were analyzed on nine acoustic characteristics including fo, duration, formant frequencies and sound pressure level. In comparison to a group of newborn controls, the Sudden Infant Death Syndrome (SIDS) victim's cries exhibited a lower fo, longer duration, lower formant frequencies and greater sound pressure level throughout the spectrum. Cry duration and sound pressure levels, however, deviated in excess on one standard deviation from the mean of the other newborns. Similar findings resulted when the SIDS infant was compared to a group of full term infants who were siblings of SIDS victims, although the magnitude of the differences was slightly less especially with respect to sound pressure level. Measurement of selected acoustic variables in a newborn's cry may be of value in our understanding of SIDS and for identifying infants at risk.

The speech spectrographic display: interpretation of visual patterns by hearing-impaired adults

If visual speech training aids are to be used effectively, it is important to assess whether hearing-impaired speakers can accurately interpret visual patterns and arrive at correct conclusions concerning the accuracy of speech production. In this investigation with the Speech Spectrographic Display (SSD), a pattern interpretation task was given to 10 hearing-impaired adults. Subjects viewed selected SSD patterns from hearing-impaired speakers, evaluated the accuracy of speech production, and identified the SSD visual features that were used in the evaluation. In general, results showed that subjects could use SSD patterns to evaluate speech production. For those pattern interpretation errors that occurred most were related either to phonetic/orthographic confusions or to misconceptions concerning production of speech.

The phonochrome: a coherent spectro-temporal representation of sound

Representation of simple stationary sounds can be given either in the temporal form by display of the waveform as function of time or in the spectral form by intensity and phase as function of frequency. For complex nonstationary sounds, e.g. animal vocalisations and human speech, a combined spectro-temporal representation is more directly associated with auditory perception. The well-known sonogram or dynamic power spectrum has a fixed spectro-temporal resolution and neglects phase relations of different spectral and temporal sound components. In this paper the complex spectro-temporal intensity density CoSTID) is presented as a coherent spectro-temporal image of a sound, based on the analytic signal representation. The CoSTID allows an arbitrary form of the spectro-temporal resolution and preserves phase relations of different sound components. Since the CoSTID is a complex function of two variables, it leads naturally to the use of colour images for the spectro-temporal representation of sound: the phonochrome. The phonochromes are shown for different technical and natural sounds. Applications of this technique for study of phonation and audition and for biomedical signal processing are indicated.

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.

Discrimination of voice onset time in infancy

In an effort to determine whether infants can discriminate speech sounds on the basis of a single acoustic cue, timing onset of periodic voicing, two experiments were conducted employing synthetic speech sounds. Naturally produced syllable pairs were also used for comparison. In the first experiment infants evidenced discrimination of a naturally produced /ba/ versus /pa/ pair and a naturally /du/ versus /tu/ pair. In addition, infants discriminated a synthetic /ba/ versus /pa/ contrast that was cued by several acoustic differences in addition to timing onset of periodic voicing but failed to evidence an ability to discriminate a synthetic /du/ versus /tu/ contrast that contained flat first formants and differed only in timing onset of periodic voicing. A second experiment was conducted in which infants once again evidenced discrimination of naturally produced /du/ versus /tu/ stimuli but not of synthetic /du/ versus /tu/ stimuli containing slight first-formant transitions. These results suggest that timing onset of periodic voicing alone may not be a sufficient cue for infant discrimination of English voicing contrasts.

Disambiguation of ditropic sentences: acoustic and phonetic cues

In a previous study, we demonstrated that listeners were highly successful in identifying the intended meaning of spoken ditropic sentences (those which may carry either a literal or an idiomatic meaning) when speakers were instructed to convey the distinction. The present communication reports on acoustic and phonetic analyses carried out with the goal of identifying cues that distinguished the literal and idiomatic utterances. Certain prosodic differences were observed. Literal utterances were systematically longer than idioms. This was partly due to increased use of pauses, as well as to increased duration of major lexical items. Moreover, literal sentences were typically characterized by greater numbers of pitch contours (discernible rise-fall excursions of fundamental frequency) and open junctures than were idiomatic utterances. In addition to suprasegmental contrasts, articulatory distinctions--corresponding to lento-allegro phonological rules--were also observed. These distinctions directly reflect the structural differences intrinsic to the two types of utterances. A literal sentence is formulated by the organization of constituent words and phrases. Idioms, on the other hand, are holistic units, largely nontransparent to syntactic structure or the usual meaning of the lexical members.

Detection of tones in band-reject noise

Three experiments were conducted to investigate the detectability of tonal signals simultaneously presented with computer-generated, long duration (.5 sec), band-reject maskers. In Experiment 1, detectability of a tone of 500, 1000, or 2000 Hz presented at 50 dB SPL was measured as a function of the width of a spectral "notch" symmetrically placed around the tone. A narrow notch resulted in decreased detectability relative to the wide band (zero-notch width) control condition. Further increases in notch width resulted in increased detectability until subjects approached errorless performance. In Experiment 2, psychometric functions were obtained for a 1000-Hz tone presented in four notch-noise conditions. The slopes of the psychometric functions were consistently steeper in the band-reject conditions relative to the zero notch-width condition. These slope differences result in relationships between threshold and notch width that depend upon the region of the psychometric function from which the threshold estimates are obtained. In Experiment 3, the decrease in performance associated with the notch was found to increase in proportion to notch depth. The data suggest that spectral edges placed in the immediate vicinity of a tone reduce the detectability of the tonal signal. This "edge effect" is discussed in relation to two-tone inhibition that has been observed in the auditory nerve.

Effects of frequency-shifted feedback on the pitch of vocal productions

Previous investigations into the effects of distorted auditory feedback on vocalizations have been limited to manipulations of intensity, background noise, temporal delay, or to selective filtering of frequency. The current study reports the results of real-time shifts of the frequency components of auditory feedback. Subjectively, such shifts are perceived primarily as an alteration in the fundamental frequency (F0) of the speech. Subjects performed a variety of tasks under conditions where they received either normal auditory feedback or frequency-shifted feedback. Under normal feedback conditions, subjects maintained approximately constant F0 as instructed. With frequency-shifted feedback, subjects attempted to compensate for the shift by adjusting their F0 up or down such that the resulting feedback appeared to be "normal."

Auditory discrimination of voiceless fricatives in children

Auditory discrimination of the voiceless fricatives magnitude of theta f integral of s was studied in 200 subjects between the ages of four and six and a half years. In the test task the subject was asked to remember one of the sounds and then to indicate each time this sound was presented. Two types of errors were analyzed. An error of omission was a failure to identify the remembered sound, and this type of error did not change with age. An error of commission, a failure to discriminate between the remembered sound and one of the other voiceless fricatives, decreased with age. The results are interpreted as support for a theory of the development of auditory perception of speech in which discrimination of some properties in speech, such as relatively weak spectral cues and second formant transitions, have to be learned by a child.

The Psychological Stress Evaluator as a clinical assessment instrument. Evaluation and implications

Efficient clinical assessment of anxiety and hostility could be facilitated through the use of a mechanical measurement instrument with known validity and reliability. Preliminary evaluation of the Psychological Stress Evaluator (PSE) has indicated that it could be used for this purpose. The present study reports the results of a correlational analysis between a PSE generated stress indicator (blocking pattern mode III) and the Gottschalk-Gleser Free Association Test, a verbal content-analysis measure of anxiety and hostility in psychotherapy patients. Findings do not show any correlation between these measures and suggest that the PSE may have only limited use as a valid and reliable assessment instrument for anxiety and hostility. Methodological problems inherent in the calculation and interpretation of PSE scores are elaborated in a review of current PSE scoring systems. A brief discussion of the theoretical assumptions underlying the development of the PSE and associated scoring protocols suggests directions for future research.

Perceptual significance of the CID W-22 carrier phrase

The 2-part study provides evidence that the carrier phrase "You will say..." contains perceptual cues which can be used by the listener to help identify place of initial consonant articulation for many test words, and when these cues are removed, the test words in isolation constitute a mre difficult word discrimination test. In the first experiment, test words beginning with voiceless stop consonants were truncated from their carrier phrases, and the phrases alone were presented to 10 normally hearing listeners. Results demonstrated above chance performance by listeners for identification of place of initial consonant articulation for the deleted test words solely on the basis of carrier phrase cues. In the second experiment, acoustically identical W-22 words with and without carrier phrases were presented to 10 normally hearing listeners at a O dB signal-to-noise ratio. A significant difference was observed in word discrimination scores for the 2 lists that can be attributed to deletion of carrier phrase cues.

Effects of domestication on production and perception of mallard maternal alarm calls: developmental lag in behavioral arousal

The process of domestication involves intense inbreeding. Field and laboratory studies were conducted to assess the effects of such intense genetic selection on the production and perception of the maternal alarm calls of domestic (Peking) and wild mallard ducks (Anas platyrhynchos). With respect to production, the calls of wild and domestic ducks were comparable in four acoustic features and differed only slightly on two features. With respect to perception, the calls of wild and domestic hens were equally effective in promoting behavioral inhibition in wild and domestic ducklings. Although these data revealed little or no effect of domestication on the structure and function of the maternal alarm call, an unexpected effect was found regarding the domestic ducklings' behavior. Specifically, Pekings showed a greater level of behavioral inhibition than did mallards at 24 hr of age. Further experiments indicated that the differential level of inhibition in the wild and domestic birds reflects a developmental lag in arousal consequent to domestication: 72-hr-old Peking ducklings are behaviorally more aroused than 24-hr-old Peking ducklings and are similar to 24-hr-old mallard ducklings in that respect. This appears to be the first demonstration of behavioral heterochrony, which is believed to be an important mechanism of behavioral evolution.

Effect of geniohyoid, cricothyroid and sternothyroid muscle stimulation on voice fundamental frequency of electrically elicited phonation in rhesus macaque

Vocalizations were elicited in three anesthetized rhesus macaques by electrical stimulation of a site in the brain stem. At the same, the laryngeal muscles--cricothyroid (CT), geniohyoid (GH) and sternothyroid (ST)--were electrically stimulated to assess their effect on the elicited phonation. Analysis of the recorded vocalizations indicated that stimulation of each of the muscles produced a substantial increase in the voice fundamental frequency (Fo), with the CT muscle causing the greatest Fo increase. Maximum elevation in Fo was obtained when the CT muscle was stimulated simultaneously with the GH or ST muscles. Changes in Fo were typically accompanied by changes in voice quality.

Perception of anticipatory coarticulation effects

Articulatory and acoustic studies have shown that the effects of anticipatory coarticulation may extend across several segments in an utterance. But previous perceptual studies suggest that only the information carried by immediately adjacent segments is used in perception. To show that perception is not so limited, we persuaded ten talkers each to produce 12 sentences (e.g., "I say poozee") of the form "I say /C V1 z V2/" in which C was /p, t, k/, V1 was /u, ae/, and V2 was /i, a/. Each /i, a/ sentence pair was cross spliced by exchanging the final syllable /z V2/ so that coarticulatory information prior to the crosspoint was inappropriate for the final vowel V2 in crossed sentences. Recognition time (RT) for V2 in crossed and intact (as spoken) sentences was obtained from practiced listeners. The results were slower RT in crossed sentences, and amount of interference depended on both V1 and C context. Another experiment varied the location of crosspoints across /C V1/ and found that RT interference increased directly with amount and proximity to target of inappropriate precross acoustics. LPC analysis of the experimental sentences showed pretarget variations in F2 frequency which were jointly dependent on identity of C, V1, and V2. Pretarget F2 variations and C and V1 identity jointly predicted amount of RT interference in crossed sentences. Finally, experiments with pretarget F2 variations in synthetic speech repeated and extended the results with real speech. These studies lead to the conclusion that the perceptual significance of coarticulation is not limited to effects on immediately adjacent segments. Listeners appear to be sensitive to many acoustic effects of the mutual influence among the segments in a sequence.

Tennessee Test of Rhythm and Intonation Patterns

The Tennessee Test of Rhythm and Intonation Patterns (T-TRIP) is a three-part suprasegmental test with 25 test items. The test items consisted of the nonsense syllable (ma) that was spoken and recorded with different rhythm and intonation patterns. Ten three-year-olds and 10 five-year-olds imitated the pattern they heard. The five-year-olds scored significantly better than the three-year-olds. The T-TRIP appears sensitive to differences between groups of different ages.

Sonority and syllabicity: acoustic correlates of perception

Evidence is accumulating that native speaker-hearers are not as consistent, confident, or in agreement, on counting the number of syllables in natural utterances as is commonly assumed. There are, however, instances where speaker-hearers give clear, consistent syllable counts. It is position of this paper that the unclear cases as well as the clear cases are phonetically classifiable in terms of sonority. The experiments presented here are intended to delimit what is meant by sonority in acoustic terms.

Laryngeal adjustments in the production of the fricative consonants and devoiced vowels in Japanese

The role of laryngeal adjustments for phonetic variations of voicing in Japanese--vowel devoicing and intervocalic /h/ voicing--was investigated using laryngeal electromyography (EMG) and fiberoptic endoscopy. The results indicated that the vowel devoicing was accompanied by EMG activity patterns of the posterior cricoarytenoid and interarytenoid different from those for fully voiced vowels, causing the glottis to be wide open. In this respect, it may be concluded that vowel devoicing mainly reflects a kind of free variation at a higher level than the EMG signals. In contrast, the voicing of /h/ occurred while the glottis remained as wide as it did for voiceless /h/ or /s/ with comparable EMG patterns of those muscles, despite the presence of vocal fold vibrations. Therefore, it may be that this latter phenomenon is chiefly dependent on some other condition at the level of the glottis.

Variability of vowel formant frequencies and the quantal theory of speech: a first report

This paper reports the results of a study in which variability of formant frequencies for different vowels was examined with regard to several predictions derived from the quantal theory of speech. Two subjects were required to reproduce eight different steady-state synthetic vowels which were presented repeatedly in a randomized order. Spectral analysis was carried out on the vocal responses in order to obtain means and standard deviations of the vowel formant frequencies. In the spirit of the quantal theory, it was predicted that the point vowel, /i/, /a/ and /u/ would show lower standard deviations than the nonpoint vowels because these vowels are assumed to be produced at places in the vocal tract where small perturbations in articulation produce only minimal changes in the resulting formant frequencies. That is, these vowels are assumed to be quantal vowels. The results of this study provided little support for the hypothesis under consideration. A discussion of the outcome of the results as well as some speculation as to its failure to find support for the quantal theory is provided in the report. Several final comments are also offered about computer simulation studies of speech production and the need for additional empirical studies on vowel production with real talkers.

Early auditory-evoked responses: spectral content

Spectral analysis of the early auditory-evoked responses in man and in the cat has shown that the predominant contribution to the total power is contained in the band below 50-100 Hz. This low-frequency content is considerably reduced when the corresponding spontaneous brain activity spectrum is subtracted from the response spectrum. Under the latter circumstances, the dominant frequency contribution is found in the 500- to 2,500- Hz bandwidth.

Identification of normal and abnormally rough vowels by spectral noise level measurements

Our goal in this study was to learn whether vowel spectral noise level (SNL) measurements might differentiate between normal and abnormally rough test vowel samples. The vowel samples studied were obtained originally for two previous investigations. In one study, 20 normal-speaking subjects phonated in isolation each of five test vowels both normally and with simulated abnormal vocal roughness. In the other, 20 subjects who individually presented a laryngeal pathology phonated each of the same test vowels in isolation. The 300 test samples available from the two studies were obtained at one intensity and mouth-to-microphone distance (75 dB SPL at 15 cm). From the original studies, narrow-band (3-Hz) acoustic spectra of the vowel samples and SNL measurements were available. For this study, a mean of 25 noise level measurements per vowel sample served as an SNL index for each test production. Additionally, for this study, the test samples were individually classified dichotomously as normal or as abnormally rough in quality by a panel of nine listeners. Data analysis resulted in the identification of an SNL mean value (termed the SNL "criterion") that appeared to differentiate effectively between the perceptually normal and abnormally rough samples of each test vowel. In general, the findings appeared to support the hypothesis that vowel SNL measurements could be used to identify normal and abnormally rough vowel samples.

The effects of presentation of noise and dental appliances on speech

The effects of dental appliances on speech were studied when subjects wore the appliances, both in quiet and in the presence of an intense noise. A group of 24 normal-speaking subjects read lists of syllables, words, and sentences and spoke spontaneously in each of six appliance and noise conditions. Several acoustic and perceptual measurements were made in each condition. In general, speech deteriorated when appliances were placed and when noise was presented. The type and amount of speech disruption varied as a function of speech task and aspect of speech. There was no evidence that the effects of appliances on speech differed in quiet and noise conditions. Inter-subject variability was large.

Identification of coarticulated vowels

Previous explanations of vowel perception held that the most definitive information for vowel identity is the relatively constant formant frequencies in the steady-state portions of vowels. Perceptual studies indicate, however, that vowels spoken in syllables with labial stop consonants are identified more accurately than vowels spoken in isolation. The present study investigated the nature and scope of this consonantal context advantage in the perception of ten American English vowels spoken by adult male and female speakers. Vowels in /p/-vowel-/p/, /b/-vowel-/b/, /k/-vowel-/k/, /k/, /k/-vowel, and vowel-/k/ syllables were identified much more accurately than isolated vowels. This is consistent with the hypothesis that dynamic acoustic information due to the coarticulation in syllables is important for vowel identification. Identification of vowels in /g/-vowel-/g/, /g/-vowel, and vowel-/g/ syllables was not better than isolated vowels and was significantly poorer than for other consonantal contexts. Acoustical analyses were performed to determine whether poor production of vowels could account for perceptual errors. Misproduced vowel targets could not account for the overall pattern of identification performance. Phonological factors were also considered but were found to be inadequate to account fully for the results.

Photoacoustics in life sciences

Photoacoustic (PA) measurements provide, by the very nature of the PA effect, the possibility to obtain information on the optical and thermal properties of samples. In addition they can yield information on the enthalpy changes and characteristic times involved in photo-induced processes as the acoustic signal is proportional to the hear produced following the absorption of the modulated excitation. In the study of optical properties the relative insensitivity to scattered light of the PA signal makes such measurement an attractive way to measure biological samples in vivo, or, at least, without the need to isolate the absorbing compounds. The dependence of the PA signal on the thermal properties of the sample is particularly useful when heterogeneous samples are studied. As a photocalorimetric method the technique shows considerable promise in the study of photo-bioenergetics, especially photosynthesis. Only in special cases can analytical applications of the PA method compete with fluorescence measurements for detection, and with increasingly sophisticated optical transmission and reflectance techniques (for identification).. However, the PA method may find important uses in fundamental research and in applied areas such as biomedicine and agricultural biochemistry.

Waveform and spectral analysis of crackles

Crackles were recorded from six patients, four with tuberculosis and two with chronic bronchitis. It was observed by waveform and spectral analysis that most of the frequency components of a crackle were limited within a range of 0.1 to 1 kHz. Characteristically, waveforms of crackles were separable into two segments, initial "starting segments" and subsequent "decay segments." It is suggested that the former represents a shock wave caused by an abrupt opening of the airway and that the latter is a damped sinusoid caused by this shock wave exciting a resonator in the lung. It is speculated that the starting segment is determined by the pressure ratio at the site of the airway opening, and the decay segment by the resonant frequency and the quality factor of the resonator. Because transmission of a crackle is highly directional the waveforms recorded on the chest wall are modified by the positional relationship between the sound source and the microphone.

Cry analysis of infants with karyotype abnormality

Sound spectrography was used to analyze 135 pain cries from 14 infants with a karyotype abnormality. At the time of the cry recording the children were from one day to seven months old, except for one child who was 2 years 10 months at the second recording. The cries were compared with 30 pain cries from 15 healthy infants of corresponding age. The children with an abnormality of chromosome 4 or 5 had cries with a significantly higher fundamental frequency than the control infants. Additionally, the cry in the "Cri-du-Chat" syndrome had a flat, monotonous melody type. The cries of infants with 13- or 18-trisomy were hoarse, low-pitched, with the shift parts absent. The cries in karyotype abnormalities were also different from pain cries of infants with other disorders involving the central nervous system. This study suggests that cry analysis can provide a valuable indication of the presence of a chromosome anomaly.

Rapid reproduction of vowel-vowel sequences: evidence for a fast and direct acoustic-motoric linkage in speech

Listeners display extremely short latencies when asked to reproduce (shadow), a random series of vowel-vowel sequences. The latency of the shadowing response is as fast or faster than that obtained when the same subjects are asked simply to produce a predetermined vowel-vowel gesture as rapidly as possible. The speed of the shadowing response suggests a fast and direct linkage of the speech-analysis and speech-production mechanisms.

A note on pitch control in esophageal speech

An unusual case of  esophageal pitch control first  discussed in this Journal is re-examined in the light of  additional data. It is claimed that high-pitched stressed vowels show evidence of  diplophonia, a possibility not described in earlier studies of  this case.