The cry latencies of normal infants and those with brain damage

Acoustic Cry Characteristics of Infants as a Marker of Neurological Dysfunction: A Systematic Review and Meta-Analysis

BACKGROUND

Atypical cries have been identified in infants with neurological dysfunction. The aim of this study was to conduct a systematic review and meta-analysis to appraise existing evidence for associations between acoustic cry characteristics and neurological dysfunction in infants aged 18 months or less.

METHODS

PubMed/MEDLINE, PsycINFO, CINAHL, and Embase were searched for original, peer-reviewed studies published in English reporting cry variables in infants aged 18 months or less with or at risk of neurological dysfunction. Studies without a nonneurologically impaired control sample were excluded. Pooled effect sizes were estimated using standardized mean difference (SMD) and odds ratio (OR). I² indicated study heterogeneity, and the risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

From March 2018 to February 2019, 28,294 studies were retrieved. Eight were meta-analyzed. Infants with or at risk of neurological dysfunction exhibited higher mean (SMD = 0.11 [95% confidence interval, 0.00 to 0.23]) and minimum (SMD = 0.93 [0.64 to 1.23]) fundamental frequency; higher odds of hyperphonation (OR = 13.17 [1.05 to 165.87]), biphonation (OR = 10.62 [1.53 to 73.59]), rise-fall-rise melodies (OR = 4.66 [1.16 to 18.66]), and flat melodies (OR = 4.47 [1.27 to 15.68]); and lower odds of fall-rise-fall melodies (OR = 0.21 [0.05 to 0.83]).

CONCLUSIONS

Infants with underlying neuropathology have unique cries characterized by higher fundamental frequency, dysphonation, and atypical melodies, although study heterogeneity and imprecision of effect size estimates limited our interpretation. Assessment of acoustic cry characteristics offers the potential for noninvasive, rapid, point-of-care screening for neurologically high-risk infants.

Acoustic quality of cry in very-low-birth-weight infants at the age of 1 1/2 years

BACKGROUND

Infant cry characteristics reflect the integrity of the central nervous system. Previous studies have shown that preterm infants and infants with neurological conditions have different cry characteristics such as fundamental frequency compared to healthy full-term infants. Cry characteristics of preterm infants after the first year of life have not been studied.

AIMS

The aim of this study was to assess the quality of cry in 1 1/2-year-old very-low-birth-weight infants (VLBWI, < or =1500 g at birth). STUDY SUBJECTS AND DESIGN: Study groups included 21 VLBWI and 25 healthy full-term controls. Thirty seconds of pain cry after vaccination was recorded at well-baby clinics. The first cry utterance was acoustically analyzed using Praat software. The quality of cry was compared between the groups. In addition, the association of cry quality to patient characteristics, to developmental outcome, and to findings in brain imaging studies of the VLBWI was studied.

RESULTS

The cry response was elicited in 20 of the 21 VLBWI and in 20 out of 25 full-term infants. VLBWI had higher minimum fundamental frequency and fourth formant values. Patient characteristics that were associated with cry quality were 5-min Apgar scores, the occurrence of bronchopulmonary dysplasia, Bayley Psychomotor Index scores at 12 months, and current weight and head circumference.

CONCLUSIONS

Differences found between the study groups were not explained primarily by brain pathology or by patient characteristics, so it seems that prematurity has an impact on cry quality still at the age of 1 1/2 years.

Ultrasonic call characteristics of rat pups are altered following prenatal malnutrition

The male offspring of rats provided with a protein deficient diet (6% casein) for 5 weeks prior to mating and throughout pregnancy were subjected to a brief period of isolation and cooling at postnatal Days (P)7, 9, and 11, and their ultrasonic vocalizations were compared with those of well-nourished pups. Calls were categorized into 12 different types based upon their sonographic patterns. Although call rates were equal, the call characteristics of the prenatally malnourished pups differed significantly from those of well-nourished controls. At P7, their mean peak sound frequency (irrespective of call type) was significantly higher, and constant frequency calls were of both higher frequency and longer duration. Over the age range studied, prenatally malnourished pups emitted a smaller variety of calls, with significantly fewer ascending frequency vocalizations while producing either significantly fewer (P9) or greater (P11) descending frequency calls. Altered crying patterns have been related to brain damage in human babies, with more abnormal cries being associated with more severe neurological impairment. Therefore, the present results most likely reflect altered central nervous system development and function. Ultrasonic vocalization characteristics in rat pups may provide a useful early marker of the severity of disturbance to the development of the central nervous system following an insult, and offer the potential for predicting the degree of functional and behavioral deficits later in life.

Neuronal networks and self-organizing maps: new computer techniques in the acoustic evaluation of the infant cry

Neuronal networks are computer-based techniques for the evaluation and control of complex information systems and processes. So far, they have been used in engineering, telecommunications, artificial speech and speech recognition. A new approach in neuronal network is the self-organizing map (Kohonen map). In the phase of 'learning', the map adapts to the patterns of the primary signals. If, the phase of 'using the map', the input signal hits the field of the primary signals, it resembles them and is called a 'winner'. In our study, we recorded the cries of newborns and young infants using digital audio tape (DAT) and a high quality microphone. The cries were elicited by tactile stimuli wearing headphones. In 27 cases, delayed auditory feedback was presented to the children using a headphone and an additional three-head tape-recorder. Spectrographic characteristics of the cries were classified by 20-step bark spectra and then applied to the neuronal networks. It was possible to recognize similarities of different cries of the same children as well as interindividual differences, which are also audible to experienced listeners. Differences were obvious in profound hearing loss. We know much about the cries of both healthy and sick infants, but a reliable investigation regimen, which can be used for clinical routine purposes, has yet not been developed. If, in the future, it becomes possible to classify spectrographic characteristics automatically, even if they are not audible, neuronal networks may be helpful in the early diagnosis of infant diseases.

Acoustical analyses of neonates' vocalizations

Crying and other vocalizations of normal children under the age of 3 days were recorded and analyzed. The purpose was to establish a norm, in acoustical terms, to which one could compare the cry of any given newborn of the same age. One hopes that such a template may assist in the identification of such neonates who have airway obstructions and/or inadequate neuromotor control of respiration. The data reveal two things. One is that the type of vocalization (cry or non-cry) is not relevant to the analysis. The other finding is that spontaneous vocalization (as distinguished from elicited vocalization) is satisfactory for the purpose.

Infants' vocalizations as a diagnostic tool

This article reviews the literature concerning infants' vocalizations and their relation to development of language and to diagnosis in studies of pathology. Some researchers believe that pre-speech vocalizations are reflexes, random activities that serve as practice for motor activities. Others believe they are directly related to the development of language. The literature reviewed dealing with the relationship between abnormal cries and pathology suggest a differential diagnosis of certain pathologies. Crying should be included in the collected symptoms to achieve a more accurate and comprehensive diagnosis.

Acoustic analysis of pathological cries, stridors and coughing sounds in infancy

In the examination of respiratory pathological sound phenomena in infancy (pathological crying, stridor and coughing sounds), besides the subjective-auditive observations and traditional examination methods (X-ray, endoscopy), acoustic analysis, as a new branch of bioacoustics, may be of much help. The various pathological infant vocalizations originating from the air passageways are merely symptoms, but they may furnish important diagnostic clues. Approximately 200 recordings of pathological sound signals derived from 180 infants suffering from 40 different diseases or anomalies were analyzed by means of sound spectrography, the fundamental frequency meter, and rarely, the minimal-time-interval spectra technique. The acoustical evaluation of the sound phenomena are not only of scientific and documentative value; they are also of great help in diagnostics and prophylaxis, in the suitable choice of diagnostic tools and in education and further training, i.e. in the everyday work of the pediatric otolaryngologist.

Food supplementation of pregnant women at risk of malnutrition and their newborns' responsiveness to stimulation

Pregnant women at risk of malnutrition were enrolled in a health care programme in Colombia, South America, and were randomly assigned to a group receiving supplementary food or to a control group at the beginning of the third trimester of pregnancy. There were no differences between the groups in social or nutritional variables. Supplementary food was found to have an effect on infants' reactions to mild aversive stimulation and their degree of irritability. Infants born to non-supplemented mothers generally responded more irritably to removal of a nipple and to the application of a cold disc to the abdomen. Female infants of non-supplemented mothers also recovered more slowly than the supplemented group from crying in response to both removal of nipple and the cold disc. The findings are believed to show a maturational effect of maternal diet during the last trimester of pregnancy.

Some developmental aspects of infants cry

Respiratory activity during crying was measured in a semilongitudianl study of 10 normal infants aged two days to eight months. Temporal aspects of respiration during crying showed marked change with age: athe duration of the expiratory phase steadily increased, while the duration of the inspiratory phase remained remarkable constant, producing an ever-lower I-fraction. A previous study reported no developmental changes in the temporal aspects of the acoustic cry signal from one to seven months of age. Reasons for the divergent findings of the present study arepresented, and it is suggested that respiratory behavior may be a better indicator of developmental changes in the crying act thanthe acoustic signal.