The intrauterine sound environment of the human fetus during labor

Decreased Right Temporal Activation and Increased Interhemispheric Connectivity in Response to Speech in Preterm Infants at Term-Equivalent Age

“…The auditory system of the human fetus is functionally developed during the last trimester of pregnancy (Birnholz and Benacerraf, 1983; Richards et al, 1992; Hepper and Shahidullah, 1994; Eldredge and Salamy, 1996; Hall, 2000). External auditory stimuli are low-pass-filtered and attenuated by maternal tissues and fluids in the uterus; however, low-frequency speech and the maternal voice are preferentially transmitted to the fetus (Querleu et al, 1988, 1989; Benzaquen et al, 1990). A number of studies have shown that near-term fetuses can discriminate sounds frequently experienced in utero , such as the mother’s voice and maternal language, from unfamiliar sounds (Fifer and Moon, 1994; Kisilevsky et al, 2003, 2009; Smith et al, 2007).…”

What sounds reach fetuses: Biological and nonbiological modeling of the transmission of pure tones

“…Transmission of acoustical signals to the fetus has been directly measured in humans using rubberwrapped microphones or hydrophones inserted: (a) in the vagina or in the cervix of pregnant or nonpregnant women (Bench, 1968;Murooka, Koie & Suda., 1976;Walker, Grimwade & Wood, 1971); and (b) in utero after the rupture of membranes, during or after labor (Benzaquen, Gagnon, Hunse, & Foreman, 1990;Gagnon, Benzaquen, & Hunse, 1992;Henshall, 1972;Johansson, Wedenberg, & Westin, 1964;Murooka et al, 1976;Nyman et al, 1991;Querleu, Renard, & Versyp, 1981;Walker et al, 1971). Given ethical considerations and the fact that when the membrane is ruptured most of the amniotic fluid escapes, thus probably modifying the in utero transmission of acoustical signals, a growing number of studies have been performed with hydrophones surgically inserted into the uterus of pregnant goats (Bench, Anderson, & Hoare, 1970) and, more frequently, pregnant sheep (Gerhardt, 1989;Vince, Armitage, Baldwin, Toner, & Moore 1982;Vince, Billing, Baldwin, Toner, & Weller, 1985).…”

Near‐term fetuses process temporal features of speech

“…Numerous studies over the past 50 years have assessed the maternal intrauterine sound environment (see review of the first studies in Busnel & Granier‐Deferre, 1983; Lecanuet et al ., 1995). Since the 1980s, power spectrum analyses of intra‐amniotic recordings in women during delivery (Benzaquen, Gagnon, Hunse & Foreman, 1990; Gagnon, Benzaquen & Hunse, 1992; Querleu, Renard, Boutteville & Crépin, 1989; Querleu, Renard & Crépin, 1981; Querleu, Renard, Versyp, Paris‐Delrue & Crépin, 1988a; Querleu, Renard, Versyp, Paris‐Delrue & Vervoot, 1988b) and in the gestating ewe (Abrams, Gerhardt & Peters, 1995; Armitage, Baldwin & Vince, 1980; Gerhardt, 1989; Peters, Abrams, Gerhardt & Griffiths, 1993; Richards, Frentzen, Gerhardt, McCann & Abrams, 1992; Vince, Billing, Baldwin, Toner & Weller, 1985) have provided a relatively clear picture of the characteristics of the sounds that can stimulate the maturing fetal auditory system. It should be mentioned here that cardio‐vascular noises are louder during delivery than during gestation (Armitage et al ., 1980; Vince et al ., 1985).…”

“…Comparison of SPL of the maternal voice measured in air and inside the amniotic fluid shows little difference. Some investigators report a small attenuation, ≤ 8 dB (Benzaquen et al ., 1990; Querleu et al ., 1988b, 1989), and others a small amplification (Richards et al ., 1992).…”