Defining and distinguishing infant behavioral states using acoustic cry analysis: is colic painful?

BACKGROUND: To characterize acoustic features of an infant's cry and use machine learning to provide an objective measurement of behavioral state in a cry-translator. To apply the cry-translation algorithm to colic hypothesizing that these cries sound painful. METHODS: Assessment of 1000 cries in a mobile app (ChatterBabyTM). Training a cry-translation algorithm by evaluating >6000 acoustic features to predict whether infant cry was due to a pain (vaccinations, ear-piercings), fussy, or hunger states. Using the algorithm to predict the behavioral state of infants with reported colic. RESULTS: The cry-translation algorithm was 90.7% accurate for identifying pain cries, and achieved 71.5% accuracy in discriminating cries from fussiness, hunger, or pain. The ChatterBaby cry-translation algorithm overwhelmingly predicted that colic cries were most likely from pain, compared to fussy and hungry states. Colic cries had average pain ratings of 73%, significantly greater than the pain measurements found in fussiness and hunger (p < 0.001, 2-sample t test). Colic cries outranked pain cries by measures of acoustic intensity, including energy, length of voiced periods, and fundamental frequency/pitch, while fussy and hungry cries showed reduced intensity measures compared to pain and colic. CONCLUSIONS: Acoustic features of cries are consistent across a diverse infant population and can be utilized as objective markers of pain, hunger, and fussiness. The ChatterBaby algorithm detected significant acoustic similarities between colic and painful cries, suggesting that they may share a neuronal pathway.

A description of externally recorded womb sounds in human subjects during gestation.

OBJECTIVE: Reducing environmental noise benefits premature infants in neonatal intensive care units (NICU), but excessive reduction may lead to sensory deprivation, compromising development. Instead of minimal noise levels, environments that mimic intrauterine soundscapes may facilitate infant development by providing a sound environment reflecting fetal life. This soundscape may support autonomic and emotional development in preterm infants. We aimed to assess the efficacy and feasibility of external non-invasive recordings in pregnant women, endeavoring to capture intra-abdominal or womb sounds during pregnancy with electronic stethoscopes and build a womb sound library to assess sound trends with gestational development. We also compared these sounds to popular commercial womb sounds marketed to new parents. STUDY DESIGN: Intra-abdominal sounds from 50 mothers in their second and third trimester (13 to 40 weeks) of pregnancy were recorded for 6 minutes in a quiet clinic room with 4 electronic stethoscopes, placed in the right upper and lower quadrants, and left upper and lower quadrants of the abdomen. These recording were partitioned into 2-minute intervals in three different positions: standing, sitting and lying supine. Maternal and gestational age, Body Mass Index (BMI) and time since last meal were collected during recordings. Recordings were analyzed using long-term average spectral and waveform analysis, and compared to sounds from non-pregnant abdomens and commercially-marketed womb sounds selected for their availability, popularity, and claims they mimic the intrauterine environment. RESULTS: Maternal sounds shared certain common characteristics, but varied with gestational age. With fetal development, the maternal abdomen filtered high (500-5,000 Hz) and mid-frequency (100-500 Hz) energy bands, but no change appeared in contributions from low-frequency signals (10-100 Hz) with gestational age. Variation appeared between mothers, suggesting a resonant chamber role for intra-abdominal space. Compared to commercially-marketed sounds, womb signals were dominated by bowel sounds, were of lower frequency, and showed more variation in intensity. CONCLUSIONS: High-fidelity intra-abdominal or womb sounds during pregnancy can be recorded non-invasively. Recordings vary with gestational age, and show a predominance of low frequency noise and bowel sounds which are distinct from popular commercial products. Such recordings may be utilized to determine whether sounds influence preterm infant development in the NICU.

A prospective observational cohort study of exposure to womb-like sounds to stabilize breathing and cardiovascular patterns in preterm neonates.

PURPOSE: We exposed premature infants to womb-like sounds to evaluate such exposure on breathing and cardiovascular patterns. We hypothesized that these sounds would reduce apnea and intermittent hypoxemia, enhance parasympathetic outflow, and improve cardiovascular patterns. METHODS: A total of 20 cases and 5 control infants at ≤32-36 weeks corrected gestational age participated in a prospective observational cohort study. Twenty-four hours of continuous ECG, respiratory and oxygen saturation data were collected in all infants. Womb-like sounds were played intermittently in 6-hour blocks. Salivary samples were collected at study beginning and end for cortisol. Apnea, intermittent hypoxemia, and bradycardia were evaluated, and heart rate variability was assessed by time domain and spectral techniques. RESULTS: Intermittent hypoxemia and bradycardia significantly declined after sound exposure. No significant differences in apnea, cortisol levels, or heart rate variability were evident among the study infants. CONCLUSIONS: Exposing premature infants to womb-like sounds has the potential to reduce hypoxemic and bradycardic events, and be used as an intervention to stabilize breathing and cardiac control in preterm infants.

Handshake-free zone in a neonatal intensive care unit: Initial feasibility study.

BACKGROUND: The handshake represents a social custom with special importance in health care settings. However, handshakes can transmit disease and compliance with hand hygiene protocols averages <50%. We hypothesized that a handshake-free zone (HFZ) could be established within our neonatal intensive care unit (NICU) and would be well-received by patient families and their health care providers (HCPs). METHODS: We established an HFZ and conducted a prospective cohort study in the NICU at 2 UCLA Medical Centers. Data collection tools included questionnaires for NICU families and their HCPs. RESULTS: Handshake greetings occurred more frequently before than during the HFZ, as reported by HCPs (P = .0002) and patient families (P = .05). Before the HFZ, physicians were more likely than nurses to shake hands with patient families (P = .001), and believe the handshake was extremely important (P = .002); during the HFZ physicians' behaviors and attitudes shifted toward those of the nurses. All patient families and 66% of HCPs believed the NICU should consider establishing an HFZ. CONCLUSIONS: The HFZ decreased the frequency of handshakes within the NICU. The influence of the HFZ on HCP behavior and attitudes varied with gender and profession. Patient families and most HCPs supported the implementation of an HFZ.