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Diplophonia has never been described in a neonate. An unusual case, then, of diplophonia in a neonate is described here. There is a description of the acoustic characteristics of this infant's cry and a discussion of their significance. This contributes to a review of the differential diagnosis of diplophonia. Moreover, this case further shows the essential relation between laryngoscopic findings and acoustical data.
The possibilities for using acoustical analysis as a noninvasive measure of the degree of obstruction created by an enlarged pharyngeal tonsil (adenoid) are discussed. The method capitalizes on the relationship which exists between a specific obstruction of the respiratory tract and the resulting respiratory sound. Results indicate that as the adenoid increases in size relative to the size of the nasopharynx, the dominant components of the respiratory sound spectrum shift towards a higher frequency range. Furthermore, the correlation found between the assessments of the obstruction due to various sizes of the adenoid by radiological methods and acoustical analyses supports the theoretical prediction that information on the size of the constriction is carried by the respiratory sound. Therefore, careful analyses of the acoustic patterns in the respiratory sound can assist in identifying constrictions and monitoring the constriction changes in the upper respiratory tract.
The vocal fundamental frequency (Fo) characteristics of four infants' hunger cries are reported. The infants were audio recorded at monthly intervals during the first year of life. In general, each infant's Fo increased across the one-year period. The increase in Fo was attributed to the transition from early reflexive crying to intentional vocalization behavior, rather than anatomical and physiological growth influences. Discussion focuses on the regulation of infant crying behavior across the first year of life, as well as the diagnostic implications of these findings.
Ontogenic changes in ultrasound production by isolated rat pups were compared in male and female pups of litters of various sex compositions. In both sexes, the peak of emission of sound around 50 kHz was on days 4-5, while 40 kHz sound production peaked on days 6-7. By days 4-5 each pulse is an inverted V-shape with frequencies between 40 and 55 kHz. At the peak of sound production, pulses with a slight downsweep from 40-45 kHz were prominent, and in the preweaning period, pulses of a relatively stable frequency of 35-40 kHz were emitted. There was a general tendency for sound pulses of female pups to be of short duration compared with those of male pups. The ontogenic changes in the ultrasonic distress call are less variable throughout all female pups of litters consisting of 2, 4, 6 or 8 female pups in a litter of 8. In contrast to this, it was found that male pups emit ultrasound more vigorously than female pups from days 2-3 to days 12-13 when male and female pups coexisted in the same litter. The activity of sound production of male pups which had no female littermates was similar to that of female pups. These findings suggest that the interaction of some kind between male and female pups produces the sex differences in the ultrasonic distress calls as early as several days after birth in the rat.
It has been recently demonstrated that application of a cholinergic agonist, carbachol, into the anterior hypothalamic-preoptic area in the rat can induce 22 kHz ultrasonic vocalization. Functional mapping of the response in the forebrain and diencephalic regions of the rat brain, as well as the relationship between the dose of carbachol and the multi-parameter recording of vocalization are analyzed in the present study. Direct pressure injection of carbachol into the brain of adapted rats induced a 22 kHz ultrasonic vocalization from a limited region of the anterior hypothalamic-preoptic area and the vicinity of the septum. The response was antagonized by a local pretreatment with atropine and could not be induced by injections of saline vehicle or by handling. Measurements of summed duration of individual calls and response duration showed a typical dose-response relationship for 32-fold range of carbachol doses with ED50 = 0.73 micrograms (4.0 nmol). The increasing dosage of carbachol did not influence the frequency of emitted ultrasounds. On the other hand, the sound intensity increased and the bandwidth decreased with the increasing dosage of carbachol. The mean duration of single calls was also significantly decreased with the carbachol dosage. However, higher doses of carbachol decreased the number of short calls (100-150 ms) but increased the number of longer calls (300-400 ms). The duration of individual calls appeared to be a sensitive index of the response intensity. The results suggest that the cholinergic input into the mediobasal forebrain may play a physiological role in initiating and emitting the 22 kHz ultrasonic vocalization in rats, and that changes in call duration, intensity and bandwidth may be involved in conveying information for conspecifics.
The metrological and computational problems of detecting very weak variations in the frequencies of the fundamental tone are discussed from a signal processing point of view. An appropriate computer method of high-resolution analysis of the fundamental frequency is proposed. When applying high-resolution fundamental frequency analysis to cry signals, a jitter was found to exist in the fundamental frequency curve of both healthy babies and those suffering from cerebral disorders. A method is given to separate the jitter from the fundamental frequency curve. The separated jitter curve depends on the degree of slope of the fundamental frequency curve and shows differences between healthy and ill babies. For an objective evaluation of the jitter abnormities, an integral parameter--the so-called cry-jitter index--is proposed.
The phonetogram represents an area limited by piano and forte contours of the sound pressure levels along the vocal range. Phonetograms are used in the diagnosis of voice status. Apart from reference phonetograms and the extraction of single parameters, phonetograms have not been evaluated quantitatively in medical practice. The present computer program divided the phonetogram into subareas which were approximated by simple patterns (ellipses). The ellipse parameters were used to evaluate voice efficiency, to recognize voice categories, and to derive diagnostic comments.
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A computer-aided system was devised to investigate the speaking space. Thirty native Cantonese speakers with Class I occlusion were selected and test sentences were designed for speech analysis by a Sona-Graph. The investigation indicated that the sibilant sounds produced the closest speaking space and that the mean and the variability of the closest speaking space in Cantonese speakers were smaller than that in English speakers. The beliefs that the closest speaking space was smaller than that of the freeway space and that the speaking space of m sound was similar to the freeway space were not supported by this study.
Secondary sound emission, partly in the audible frequency range, from shock wave disintegration of kidney stones has been recorded during the treatment of two patients. A skilled operator can determine by listening if the stone is hit by the shock-wave or not. Spectral analysis of these recordings show differences between the sounds which can be used to evaluate the fragmenting effect on the stone. Results are presented of a preliminary discriminating method based on parameters in an autoregressive signal model.
Fourteen infants who were undergoing routine immunization were studied from a multidimensional perspective. The measures used were heart rate, crying, body movement/posturing, and voice spectrographs. There was wide variability between infants on the measures, especially on the cry spectrographs, although facial expression was consistent across infants. The pattern that did emerge was characterized by an initial response: a drop in heart rate, a long, high pitched cry followed by a period of apnea, rigidity of the torso and limbs, and a facial expression of pain. This was followed by a sharp increase in heart rate, lower pitched, but dysphonated cries, less body rigidity, but still facial expression was of pain. Finally, in the second half of the minute's response, heart rate remained elevated, cries were lower pitched, more rhythmic, with a rising-falling pattern, and were mostly phonated, and body posturing returned to normal. Those faces that could be viewed also were returning to the at rest configuration. It was suggested that facial expression may be the most consistent across-infant indicator of pain at this point in time.
A cotton tip applicator was utilized to stimulate far IR scatter (emission) from human breath. The reticulated cotton tip was vibrated at 200 Hz, the acoustic frequency that matches the average vibration frequency of common species of mosquitoes. Mosquitoes have open resonator dielectric sensillae (spines) on their antenna that match the 643 cm-1 (15.5) Cabannes line in the 667 cm-1 region of CO2 rotation line, acoustic Stokes Brillouin and Stokes Raman lines are noted. Implications of such maserlike (coherent or partial coherent) scatter lines to insect control and disease diagnostics are discussed.
Sound spectrographic cry analysis was performed on 302 cries of 48 preterm infants born at 30-37 gestational weeks. The cries were recorded during the first week of life and thereafter weekly until the infants were discharged. The control series comprised 54 cries from 27 fullterm healthy infants. The results showed that the cries of the smallest prematures compared with the controls were shorter, more high-pitched, and included bi-phonation and glide more often. The cry characteristics changed with increasing conceptual age and the older the child the more the cry pattern resembled that of the fullterm. The cries of the preterm infants when they had reached 38 conceptual weeks were similar to those of newly born fullterm infants. The results indicate that the gestational age should be taken into consideration in cry analysis.
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.
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.
Studies dealing with auditory information processing often present the dynamic spectrum of the sound stimulus (sonogram) in addition to the stimulus waveform. The sonogram, presenting the spectral and temporal properties of the sound in a combined way, reflects properties that are assumed relevant in central information processing. For 12 neurons recorded from the midbrain of the grass frog the sonogram of a Gaussian wide-band noise stimulus was correlated with the output of the neuron to that noise. From this input-output correlogram the spectro-temporal receptive field (STRF) was calculated. The STRF reflects those spectral and temporal properties of the stimulus that influence the firing probability of the neuron. A quantitative procedure was developed to calculate the neuron's response as far as it could be derived from the STRF. This procedure basically consisted of a convolution between STRF and the sonogram of the stimulus followed by a summation over the various frequency bands. In this way it proved possible to estimate to what extent the STRF characterised the neuron's firing behaviour. Heuristic approaches, in which the neuron was modelled to a parallel series of band-pass filters, a summator and a static nonlinearity, representing a spike-generating mechanism, resulted in a considerable improvement of the characterisation.
The spectro-temporal receptive field (STRF) of an auditory neuron represents those characteristics of the sound stimulus in both the time and frequency domain that affect the firing probability of the neuron. The STRF is determined under stationary stimulus conditions for Gaussian wide-band noise. It has been demonstrated that for some neurons the response to that noise could to a considerable extent be derived from the STRF. In the present study the usefulness of the STRF is tested to predict responses to other stimuli such as noise with different frequency content and to species-specific vocalisations. It appears that the predicted response to vocalisations is at best in qualitative agreement with the actual response.