Advertisement

Evaluation of fetal exposure to external loud noise using a sheep model: quantification of in utero acoustic transmission across the human audio range

      Background

      There is mounting evidence that neural memory traces are formed by auditory learning in utero and that premature newborns are particularly sensitive to the intense, sustained noises or impulses sounds associated with the use of intensive care equipment. One area of critical importance is the determination of sound level exposure in utero associated with maternal occupation. The attenuation factors provided by the abdomen and tissue as well as the routes by which the inner ear receives stimulation need careful consideration and investigation to provide prenatal protection from external sound levels and frequencies that may cause harm.

      Objective

      To measure how sound from external sound sources is transmitted to the fetus inside the uterus of a pregnant sheep in 6 Hz frequency steps between 100 Hz and 20 kHz (ie, across most of the human audio range).

      Study Design

      We measured acoustic transfer characteristics in vivo in 6 time-mated singleton pregnant Romney ewes (gestational age, 103–130 days, weight, 54–74 kg). Under general anesthesia and at hysterotomy, a calibrated hydrophone was attached to the occiput of the fetal head within the amniotic sac. Two calibrated microphones were positioned in the operating theater, close to the head and to the body of each ewe. Initial experiments were carried out on 3 pregnant ewes 3 days after transport recovery to inform the data acquisition protocol. This was followed by detailed data acquisition of 3 pregnant ewes under general anesthesia, using external white noise signals. Voltage signals were acquired with 2 calibrated microphones, located near the head and the body of each ewe and with a calibrated hydrophone located in the amniotic fluid.

      Results

      Measurement of acoustic transmission through the maternal abdominal and uterine walls indicates that frequency contents above 10 kHz are transmitted into the amniotic sac and that some frequencies are attenuated by as little as 3 dB.

      Conclusion

      This study provides new data about in utero sound transmission of external noise sources beyond physiological noise (cardiovascular, respiratory, and intestinal sounds), which help quantity the potential for fetal physiological damage resulting from exposure to high levels of noise during pregnancy. Fine-frequency acoustic attenuation characteristics are essential to inform standards and clinical recommendations on exposure of pregnant women to noise. Such transfer functions may also inform the design of filters to produce an optimal acoustic setting for maternal occupational noise exposure, use of magnetic resonance imaging during pregnancy, and for neonatal incubators.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Birnholz J.C.
        • Benacerraf B.R.
        The development of human fetal hearing.
        Science. 1983; 222: 516-518
        • Jardri R.
        • Pins D.
        • Houfflin-Debarge V.
        • et al.
        Fetal cortical activation to sound at 33 weeks of gestation: a functional MRI study.
        Neuroimage. 2008; 42: 10-18
        • Jardri R.
        • Houfflin-Debarge V.
        • Delion P.
        • Pruvo J.P.
        • Thomas P.
        • Pins D.
        Assessing fetal response to maternal speech using a noninvasive functional brain imaging technique.
        Int J Dev Neurosci. 2012; 30: 159-161
        • Partanen E.
        • Kujala T.
        • Näätänen R.
        • Liitola A.
        • Sambeth A.
        • Huotilainen M.
        Learning-induced neural plasticity of speech processing before birth.
        Proc Natl Acad Sci USA. 2013; 110: 15145-15150
        • Partanen E.
        • Kujala T.
        • Tervaniemi M.
        • Huotilainen M.
        Prenatal music exposure induces long-term neural effects.
        PLoS One. 2013; 8: e78946
        • Lary S.
        • Briassoulis G.
        • de Vries L.
        • Dubowitz L.M.
        • Dubowitz V.
        Hearing threshold in preterm and term infants by auditory brainstem response.
        J Pediatr. 1985; 107: 593-599
        • Abrams R.M.
        • Gerhardt K.J.
        The acoustic environment and physiological responses of the fetus.
        J Perinatol. 2000; 20: S31-S36
        • Gerhardt K.J.
        • Abrams R.M.
        • Oliver C.C.
        Sound environment of the fetal sheep.
        Am J Obstet Gynecol. 1990; 162: 282-287
        • Gerhardt K.J.
        • Pierson L.L.
        • Huang X.
        • Abrams R.M.
        • Rarey K.E.
        Effects of intense noise exposure on fetal sheep auditory brain stem response and inner ear histology.
        Ear Hear. 1999; 20: 21-32
        • Xyrichis A.
        • Wynne J.
        • Mackrill J.
        • Rafferty A.M.
        • Carlyle A.
        Noise pollution in hospitals.
        BMJ. 2018; 363: k4808
        • American Academy of Pediatrics Committee on Environmental Health
        Noise: a hazard for the fetus and newborn.
        Pediatrics. 1997; : 724-727
        • Nieuwenhuijsen M.J.
        • Ristovska G.
        • Dadvand P.
        WHO environmental noise guidelines for the European Region: a systematic review on environmental noise and adverse birth outcomes.
        Int J Environ Res Public Health. 2017; 14
        • Selander J.
        • Albin M.
        • Rosenhall U.
        • Rylander L.
        • Lewné M.
        • Gustavsson P.
        Maternal occupational exposure to noise during pregnancy and hearing dysfunction in children: a nationwide prospective cohort study in Sweden.
        Environ Health Perspect. 2016; 124: 855-860
        • Selander J.
        • Rylander L.
        • Albin M.
        • Rosenhall U.
        • Lewné M.
        • Gustavsson P.
        Full-time exposure to occupational noise during pregnancy was associated with reduced birth weight in a nationwide cohort study of Swedish women.
        Sci Total Environ. 2019; 651: 1137-1143
        • Lasky R.E.
        • Williams A.L.
        The development of the auditory system from conception to term.
        Neo Reviews. 2005; 6: e141-e152
        • Griffiths S.K.
        • Brown Jr., W.S.
        • Gerhardt K.J.
        • Abrams R.M.
        • Morris R.J.
        The perception of speech sounds recorded within the uterus of a pregnant sheep.
        J Acoust Soc Am. 1994; 96: 2055-2063
        • Graham E.M.
        • Peters A.J.
        • Abrams R.M.
        • Gerhardt K.J.
        • Burchfield D.J.
        Intraabdominal sound levels during vibroacoustic stimulation.
        Am J Obstet Gynecol. 1991; 164: 1140-1144
        • Mehta V.
        • Abi-Nader K.N.
        • Peebles D.M.
        • et al.
        Local over-expression of human VEGF-A165 in the mid-gestation pregnant sheep uterine artery leads to a sustained increase in uterine artery blood flow and altered vascular reactivity.
        Gene Therapy. 2011; 15: 1344-1345
        • Jones A.K.
        • Gately R.E.
        • McFadden K.K.
        • Zinn S.A.
        • Govoni K.E.
        • Reed S.A.
        Transabdominal ultrasound for detection of pregnancy, fetal and placental landmarks, and fetal age before Day 45 of gestation in the sheep.
        Theriogenology. 2016; 85: 939-945
        • Abi-Nader K.N.
        • Mehta V.
        • Shaw S.W.
        • et al.
        Telemetric monitoring of fetal blood pressure and heart rate in the freely moving pregnant sheep: a feasibility study.
        Lab Anim. 2011; 45: 50-54
        • Moon C.
        • Lagercrantz H.
        • Kuhl P.
        Language experienced in utero affects vowel perception after birth: a two-country study.
        Acta Paedr. 2013; 102: 156-160
        • Gerhardt K.J.
        • Huang X.
        • Arrington K.E.
        • Meixner K.
        • Abrams R.M.
        • Antonelli P.J.
        Fetal sheep in utero hear through bone conduction.
        Am J Otolaryngol. 1996; 17: 374-379
        • Richards D.S.
        • Frentzen B.
        • Gerhardt K.J.
        • McCann M.E.
        • Abrams R.M.
        Sound levels in the human uterus.
        Obstet Gynecol. 1992; 80: 186-190
        • Lecanuet J.P.
        • Gautheron B.
        • Locatelli A.
        • Schaal B.
        • Jacquet A.Y.
        • Busnel M.C.
        What sounds reach fetuses: biological and nonbiological modeling of the transmission of pure tones.
        Dev Psychobiol. 1998; 33: 203-219
        • Wang P.I.
        • Cheng S.T.
        • Kielar A.Z.
        • et al.
        Imaging of pregnant and lactating patients. Part 1: evidence-based review and recommendation.
        Am J Roentgenol. 2012; 198: 778-784
        • Ray J.G.
        • Vermeulen M.J.
        • Bharatha A.
        • Montanera W.J.
        • Park A.L.
        Association between MRI exposure during pregnancy and fetal and childhood outcomes.
        JAMA. 2016; 316: 952-961
        • Bouyssi-Kobar M.
        • du Plessis A.J.
        • Robertson R.L.
        • Limperopoulos C.
        Fetal magnetic resonance imaging: exposure times and functional outcomes at preschool age.
        Pediatr Radiol. 2015; 45: 1823-1830
        • Jahn M.
        • Müller-Mazzotta J.
        • Arabin B.
        Music devices for the fetus? An evaluation of pregnancy music belts.
        J Perinat Med. 2016; 44: 637-643
        • Saliba S.
        • Esseily R.
        • Filippa M.
        • Kuhn P.
        • Gratier M.
        Exposure to human voices has beneficial effects on preterm infants in the neonatal intensive care unit.
        Acta Paediatr. 2018; 107: 1122-1130
        • Lejeune F.
        • Lordier L.
        • Pittet M.P.
        • et al.
        Effects of an early postnatal music intervention on cognitive and emotional development in preterm children at 12 and 24 months: preliminary findings.
        Front Psychol. 2019; 10: 494
        • Lordier L.
        • Loukas S.
        • Grouiller F.
        • et al.
        Music processing in preterm and full-term newborns: a psychophysiological interaction (PPI) approach in neonatal fMRI.
        Neuroimage. 2019; 185: 857-864