Scientists have known that the first step in hair cell birth starts at the outermost part of the spiraled cochlea
. Here, precursor cells start transforming into hair cells.
Twenty-one papers summarize recent findings on the mechanisms that underlie sharp frequency tuning in the auditory system, how temporal information is encoded in the cochlea
and transmitted to the brain, and how the latter can provide top-down control of sound processing.
The mammalian cochlea
, an excellent sensory organ, is sensitive to sound and can discriminate frequencies exquisitely .
The conversion of sound waves to nerve impulses takes place in the inner ear, also known as the cochlea
, which looks like the spiral shell that some snails have.
In patients with worsened hearing, the mean cochlear volume was 0.08 [+ or -] 0.07 cm3 (0.02-0.15 cm3), the mean TV was 7.1 [+ or -] 6 cm3 (1-15 cm3), the mean maximum dose to the cochlea
was 5.1 [+ or -] 2.1 Gy (3-7.3 Gy), and the mean minimal dose to the cochlea
was 12.6 [+ or -] 5.6 Gy (9-21 Gy).
The cochlear implant electrode was found in the cochlea
. Air shadow was detected in the inner ear, including cochlea
, vestibule and semicircular canals (Figure 1b).
Exposure to noise causes the increase of reactive oxygen species (ROS) and free radicals in the cochlea
, which due to overactivation of mitochondria, enzymatic reactions.
* Sensorineural--in which sound reaches the cochlea
without trouble, but because of damage to the cochlea
itself, or to the auditory nerve, the sound cannot be properly converted into nerve impulses that reach the brain.
In this context, Mohamed El Shazly, president of Egypt Cochlea
2018 conference and president of Cochlear Implant Unit in Wadi El Neel Hospital, said that there are more than 7,000 Egyptian children who need cochlear implant surgery annually and that, according to statistics and the World Health organisation, 1,500 Egyptian children undergo cochlear implants annually.
The maturation of the cochlea
, which is the peripheral auditory system, is also completed after birth.
Jo Milne, of Low Fell, who made headlines when cochlea
implants enabled her to hear for the first time.
ROUGHNESS PERCEPTION OF TWO TONES RECEIVED simultaneously by the ear is related to critical band, a range of frequencies in which there is competition for the same region of the cochlea
in the inner ear.
In addition, blood flow in the cochlea
has been well known as an critical factor for hearing function, and vasoconstriction induced by noise clearly contributes to NIHL [2-4].
Exposure to continuous or impulse noise can cause mechanical damage and metabolic disruptions in the cochlea
of the inner ear [4, 5].
Among these, mention should be made of artificial cochlea
implants, offering the best rehabilitation of hearing and speech for children and adults with hearing loss.