Temporal bone study of development of the organ of Corti: correlation between auditory function and anatomical structure.
Level 4 - case-series / case-control
Descriptive post-mortem histological case series of human fetal tissue specimens.
PubMed 17367561 · doi:10.1017/S0022215107006548
What was done
Researchers examined step sections of 81 human fetal temporal bones from 8 weeks of gestation to full term to characterize the morphological development of the organ of Corti in the human cochlea.
What was found
By the 10th week, the tectorial membrane primordium reached the most apical turns. At 14 weeks, hair cells were identifiable at the basal turn alongside an oval space between inner and outer hair cells. Hensen's cells were recognised at 14 to 15 weeks, individual pillar cells were identifiable at 17 weeks, and the tunnel of Corti opened at 20 weeks. By 25 weeks, the cochlea reached adult size, with fine structural maturation continuing until full term.
Why it matters
This timeline demonstrates that the anatomical foundation for fetal hearing is established by 20 weeks of gestation, with continued structural maturation likely influencing auditory mechanical properties in preterm infants.
Limits
The study is purely histological and descriptive; it does not directly measure auditory physiology or functional hearing in the fetuses. The abstract does not report the distribution of gestational ages across the 81 specimens or maternal/fetal clinical characteristics.
Cited by
- supports The human organ of hearing is fully formed in utero.
- supports Human fetuses begin to hear or sense mechanical sound waves in the second trimester.