The purpose of this study is to identify problems with interpreting sounds in babies that have been exposed to opioids prior to birth. Being able to identify these issues in infancy may allow us to find children who may have problems with language learning later in life so that we can try to minimize these.

This is a single center prospective study of neonates >36 weeks' gestation prenatally exposed to psychoactive substances and gestationally age-matched controls. Evoked response potentials on EEG in response to auditory oddball paradigms will be compared between cohorts. Analyses will try to identify differences in auditory processing using ANOVAs to compare the mismatch negativity measures, amplitudes and latencies as a function of study group.

Inclusion Criteria:

• Gestational age ≥ 36 weeks, confirmation of dates via ultrasound or last menstrual period
• Prenatal opioid exposure ("exposed"), confirmed via admitted use or newborn drug screen; no prenatal opioid exposure ("control") by maternal report or testing
• All races, ethnicities, sexes to be included
• Informed permission form signed by mother

Exclusion Criteria:

• Birth weight ≤ 3rd percentile or ≥ 97th percentile for gestational age
• Have comorbid medical disorders including; those associated with sensorineural hearing loss, significant congenital anomalies, congenital heart disease, known brain injury/malformations
• Infants requiring mechanical ventilation
• Infants requiring continuous sedation

Investigators with routine access to infant and maternal records will identify subjects based on review of patient charts upon admission to the NICU or nursery.