Proper development of the hearing is extremely important in the later process of hearing and speech understanding. The human ear can be functionally divided into four main sections: the external ear, the middle ear, the inner ear, and the hearing processing centers of the brain. All four parts work together to conduct sounds from outside the head to the brain and to process it. Maturation of ear structures is the process of conditioning the ontogenetic development and has a significant impact on the subsequent functioning of the child in the broadly defined processes of cognition.

Human’s prenatal development is divided into two periods: embryonic (since fertilization until 8th week) and fetal (9th until birth). In these periods ontogenetic development of hearing is recognized:

EMBRYONIC PERIOD

  • Day 19-21 – auditory plate
  • Day 23-36 – otocyst
  • Day 31-35 – morphological differentiation of the membranous labyrinth
  • Day 37-42 – development of semicircular ducts
  • Day 44-48 – turns of the cochlea arise
  • Day 48-51 – completely formed: semicircular ducts, cochlear duct, auditory ossicles, auricle
  • Day 56-60 – external acoustic meatus

 

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In order to check whether all the elements of the auditory pathway have been formed properly in 1-2 days after birth the otoacoustic emission (OAE) is performed .

FETUS PERIOD

  • Week 8-20 – ampullary cupula
  • Week 10 – scala tympani, labyrinthine
  • Week 11-12 – development of organ of Corti
  • Week 12 – tympanic membrane
  • Week 16 – macula of saccule and utricle
  • Week 20-21 – fully developed organ of Corti
  • Week 23 – developed bony labyrinth
  • Week 28-29 – development of pneumatic system of the ear
  • Week 24-36 – final form of auditory ossicles

 

 


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Based on the: Obrębowski A., Podstawowe wiadomości z filo- i ontogenezy oraz anatomii narządu słuchu („Basics of phylogenetics and ontogentics” at „Audiologia kliniczna”(Clinical audiology handbook), Pruszewicz A, Obrębowski A. (editor)., Poznań 2010