Short Note on Human Ear
We hear the sound by ear. Ear has three parts:
Outer Ear:
This is horn like part, which we can see outside. This ear collects the sound waves and directs them to eardrum. Eardrum separates the outer ear from middle ear.
Middle Ear:
Eardrum passes the collected vibrations of sound to middle ear. This ear is small irregular cavity. It consists of three moveable bones called hammer, anvil and stirrup.
Inner Ear:
Vibrations of the eardrum are passed to the inner ear. This ear has complicated structure. It plays an important role in hearing. It has a part cochlea. Then these sounds waves converted into messages and send to brain by auditory nerve. Then we recognize the sound.
Maintaining Balancing & Posture:
Balancing is done by the following structures:
- i) 3-semicircular canals
- ii) Utricles
iii) Sacculus
Any defect in these structures causes dizziness and loss of balance.
The complete set of the product differs from company to company. It may not include a cover, stand, memory card, headphones. The charger can be a cable for communication with a computer via a USB port. In this case, it is better to purchase it additionally with a connection to a regular electrical outlet. The complete set is indicated in the technical specifications of the product. Additional purchase of accessories will affect the total cost. What to choose The creators of e-books are developing to introduce a color screen with e-ink technology E-Ink. However, digital textbooks must have additional features and built-in applications. Not everyone has such developments. Several companies have become leaders in the provision of electronic textbooks