PubMed Health⌕ Search

Biomedical subjects

L Paris-Delrue

Publications and source records attributed to L Paris-Delrue.

3 recordsLinked to original sources
PubMed1988

Fetal hearing.

The fetus can hear during the last trimester of pregnancy. Consistent responses to acoustic stimuli have been observed from 28 weeks onwards. Animal experiments as well as investigations in the human lead to the conclusion that sounds from outside the mother are attenuated, but rarely by more than 30 decibels; external conversations are audible. Only 30% of the phonetic information is available to the fetus, but intonation is almost perfectly transmitted to the amniotic sac. Evidence is accumulating that the mother's voice or different sound patterns from the same voice are learnt by the fetus. Thus there are indications that short-term auditory memory may be present by the end of pregnancy.

Auditory Perception↗
PubMed1988

[Intra-amniotic transmission of the human voice].

New acoustic measurements in amniotic environment permit to specify the conditions of transmission of human voices: voices emerge, incompletely covered by a low background noise, but however higher pitched near the placenta. The recognition of phonemes in utero is rather weak, approximately 30 per cent and appreciably identical for all voices and different mode of emission. Therefore this type of recognition is likely to play a minor role: the voices are evenly toneless by lack of high-pitch, and there is no obvious superiority of the intelligibility of direct maternal voice. The recognition of vowels by their second forming, as well as the emergence (demonstrated with special microphones) of impulse noises with very high-pitch components and of synthetic speech, confirm the possibility of transmission of frequencies exceeding 1,500 Hz to the intra-amniotic environment. On the contrary, melody recognition is excellent: probably major role of this factor. The loudness of the maternal voice transmitted to the uterus exceeds markedly that of outside voices, and this voice is certainly accessible to the fetus, most of the time. The demonstration of the transmission to the amniotic fluid of noises and voices enables to consider the possibility of perception.

Amniotic Fluid↗