Sound is a form of energy and transfer in form of wave to the listener through a medium by vibration Sound is transmitted through a medium in the form of vibration or wave reach the human ear , the waves as sound
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Sound are classified into two classes (i) musical sound (ii) noise
Musical sounds are caused by bodies performing regular vibration. Examples of musical instruments are flute, trumpet, drum, guitar, piano and gong.
Noises are caused by irregular disturbances such as collision and explosion.
Sound requires a medium in order to travel. It can travel through the wire as well as through the air . Sound is also transmitted metals and pipes. The sound may converted to electrical signals when travel through a long distance as in the case of land telephone. Sound waves can be reflected in the same way as light wave when strike a hard surface such as wall, rock or concrete structures. The reflection of sound waves when obstructed by hard object such as rock is called echo.
Sound waves can also be refracted when it passes from one medium to another. Sound can also undergo diffraction and interference.
Characteristics of sound waves
– Reflect
– Refract
– It needs medium to travel , it is fastest in solid
Mechanism of Hearing
Souns waves entering the pinnae are directed into the auditory canal which make the eardrum to vibrate .The vibration sets the ossicles into a greater vibration. This vibration greatly amplified in the middle ear, which cause the oval window to vibrate far more than the eardrum because of its smaller size. The vibration in the oval window are passed on to the endolymph in the cochlea and cause the membrane carrying hair cells to vibrate .The vibration make the hair cell to set up a nerve impulse. The is carried through the auditory nerve to auditory region of the brain where is interpreted as sound.
ASSINGMENTS
1. All objects that produce sound have a common characteristic called A. vibration B. tuning fork C pieces metal D. sound
2. One of the characteristic of sound energy similar to light energy is A. incidence B. deviation C. refraction D. reflection
3. The part of the hear that is responsible for hearing is A. semicircular canals B. auditory nerve C. eardrum D. pinna
4. The hole through which sound enters the human ear is called A. tympanic membrane B. auditory meatus C. semi-circular canals
5. Echo is produced when sound is A. incident B. blocked C. refracted D. reflected
6. The matter through which sound is transmitted is called A. medium B. gong C. flute D. microphone
- The bonelike structures found in middle ear is called A. blade B. earbone C. ossicles D. pinna
- Optic nerve is to eye as ____________ nerve is to the ear A. auditory B. nerve endings C. olfactory D. papillae
9 a. Define sound
b. State the S.I unit of sound energy
c. State four characteristics of sound
See also
Resources from non-living things and their Location of solid mineral in Nigeria
Resources from Non-living Things (Solid Material)
Economic Importance of Plant and Animal Resources