Subject: A question about pre-natal hearing From: Jan Schnupp <jan.schnupp@xxxxxxxx> Date: Sun, 1 Mar 2015 19:22:26 +0000 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--047d7b4145d8d8c5df05103f06f6 Content-Type: text/plain; charset=UTF-8 Dear List, I was looking around for literature describing the intra-uterine sound environment of unborn fetuses and came across this paper http://journals.lww.com/greenjournal/abstract/1992/08000/sound_levels_in_the_human_uterus.6.aspx which suggests that sound in the uterus - if measured with a hydrophone - is essentially unattenuated relative to the source of air born sound and shows apparently no low-passing. That would suggest that sound in utero is essentially crystal clear and not "muffled" as one might perhaps intuitively suspect. However, as I was pondering this I wondered: what about the middle ear of unborn children? Are they filled with (amniotic?) fluid? Or with air? And does it matter? How good could we expect the cochlea in the unborn to be at picking up sound from the amniotic fluid, and does that depend on whether the middle ear is fluid or air filled? Best wishes, Jan -- Prof Jan Schnupp University of Oxford Dept. of Physiology, Anatomy and Genetics Sherrington Building - Parks Road Oxford OX1 3PT - UK +44-1865-282012 http://jan.schnupp.net --047d7b4145d8d8c5df05103f06f6 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">Dear List,<div><br></div><div>I was looking around for lit= erature describing the intra-uterine sound environment of unborn fetuses an= d came across this paper</div><div><a href=3D"http://journals.lww.com/green= journal/abstract/1992/08000/sound_levels_in_the_human_uterus.6.aspx">http:/= /journals.lww.com/greenjournal/abstract/1992/08000/sound_levels_in_the_huma= n_uterus.6.aspx</a><br></div><div>which suggests that sound in the uterus -= if measured with a hydrophone - is essentially unattenuated relative to th= e source of air born sound and shows apparently no low-passing. That would = suggest that sound in utero is essentially crystal clear and not "muff= led" as one might perhaps intuitively suspect. However, as I was ponde= ring this I wondered: what about the middle ear of unborn children? Are the= y filled with (amniotic?) fluid? Or with air? And does it matter? How good = could we expect the cochlea in the unborn to be at picking up sound from th= e amniotic fluid, and does that depend on whether the middle ear is fluid o= r air filled?</div><div><br></div><div>Best wishes,</div><div><br></div><di= v>Jan</div><div>=C2=A0<br clear=3D"all"><div><br></div>-- <br><div class=3D= "gmail_signature">Prof Jan Schnupp<br>University of Oxford<br>Dept. of Phys= iology, Anatomy and Genetics<br>Sherrington Building - Parks Road<br>Oxford= OX1 3PT - UK<br>+44-1865-282012<br><a href=3D"http://jan.schnupp.net" targ= et=3D"_blank">http://jan.schnupp.net</a></div> </div></div> --047d7b4145d8d8c5df05103f06f6--