Cervical Auscultation Of Suckle Feeding In Newborn Infants

Abstract

SUMMARY The authors recorded the sound signals during suckle feeding of six normal infants within the first two postnatal days. The sounds were recorded onto a cassette tape‐recorder from a small microphone attached to the infant's neck, then displayed on an oscilloscope and analysed by digital signal processing techniques. These displays demonstrated acoustic patterns and temporal relationships which are not otherwise audible. The method and findings are described in detail, and the method should be useful in the clinical investigation of feeding and swallowing problems associated with more subtle neurological impairment and preterm birth. RÉSUMÉ Auscultation cervicale de I'allaitement chez le nouveau‐né Les auteurs ont enregistré les signaux sonores de six nouveaux‐nés normaux durant l'allaitement, les deux premiers jours post‐nataux. Les sons ont été enregistrés sur cassette magnétique à partir d'un petit microphone attaché au cou du nourrisson, puis transmis sur oscilloscope et analysés par les procédés habituels de traitement de signal. La transcription révélait des groupements acoustiques et des relations temporelles non directement audibles. La méthode et les résultats sont décrits en détail et la méthode peut être utile dans l'investigation clinique de l'allaitement et des problèmes de déglutition associés à un trouble neurologique mineur ou à une naissance prématurée. ZUSAMMENFASSUNG Cervicale Auskultation während des Trinkens bei Neugeborenen Die Autoren haben die Geräusche beim Trinken bei sechs gesunden Neugeborenen in den ersten zwei Tagen nach der Geburt aufgenommen. Die Geräusche wurden über ein kleines Mikrophon, das am Hals des Kindes befestigt war, mit einem Kassettenrekorder aufgenommen, auf einen Oszillographen übertragen und mit Hilfe einer digitalen Signalverarbeitungstechnik analysiert. Diese Aufschlüsselungen zeigten akustische Muster und zeitliche Zusammenhänge, die sonst nicht wahrnehmbar sind. Methode und Befunde werden genau beschrieben. Die Methode sollte bei der klinischen Untersuchung von Fütterungs‐ und Schluckproblemen in Verbindung mit subtilen neurologischen Störungen und Frühgeburt eine Hilfe sein. RESUMEN Auscultación cervical en la succión de alimento en los recién nacidos Los autores registraron las señales acústicas durante la succión de alimento en seis lactantes normales en el curso de los dias postnatales. Los sonidos se registraron en un cassette a partir de un pequeño micrófono fijado al cuello del niño y luego observados en un osciloscopio y analizados por técnicas de procesamiento de señal digital. De esta forma se demostraron patrones acústicos y relaciones temporales que de otra forma no son audibles. Se describen con detalle el método y los hallazgos. El método seria útil en la investigación clinica de la deglució y de los problemas de ella y de la alimentacion, asociados con alteraciones sutiles neurológicas y con el nacimiento pretérmino.

Variability of Swallow-associated Sounds in Adults and Infants

“…CA has been used to describe infant cry [9,10], pharyngeal action during birth [11], and cry and feeding of infants with cleft palate [12]. CA with digital signal processing has been used to identify discrete sounds, called initial discrete sounds (IDSs) and final discrete sounds (FDSs), which are consistently associated with swallow in healthy term infants [13,14]. The developmental progression of the IDS waveform in healthy preterm infants and infants with bronchopulmonary dysplasia has been identified [1,2].…”

“…This is advantageous as long as the target signal is in the frequency range where the curve is above zero. For most microphones, the frequency response curve is positive in the range of audible human hearing (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). At frequencies at which the curve is less than zero, the signal is attenuated or not detected.…”

“…Vice et al [13,14] used cervical auscultation with an accelerometer to evaluate rhythmic suckle feeding in newborn infants. They identified discrete and reproducible swallow-associated signals that they called initial discrete sounds (IDS) and final discrete sounds (FDS) in recognition of their temporal relationship to pharyngeal pressure change during swallow.…”

Doppler sonar analysis of swallowing sounds in normal pediatric individuals

“…The most prominent acoustic characteristic of the swallowing sound corresponding to food movement through the upper esophageal sphincter is found where the movements of the hyoid bone, the larynx and the epiglottis contributes to the swallowing acoustic signal 11 . The respiratory action of the upper airways and the sudden changes in the respective muscles during the swallowing pharyngeal phase are also described as sound components 12 .…”

Anthropometric and Demographic Correlates of Dual-Axis Swallowing Accelerometry Signal Characteristics: A Canonical Correlation Analysis

“…Both swallowing accelerometry and cervical auscultation have been proposed as potentially useful and minimally invasive methods for detecting abnormalities in swallowing. Early reports of swallowing sounds, heard either through a stethoscope or a microphone, described a characteristic sound pattern involving a sequence of two clicks, followed by a ''swoosh'' sound [1]. Previous research has explored methodologic aspects of auscultation [2], including the benefits of using different stethoscopes [3] and the best locations on the neck for collecting swallowing sounds, based on the harmonic-to-noise ratio [4,5].…”