FREQUENCY AND AMPLITUDE HUMAN EAR TUNING FORK
VIDEO SUMMARY
CBSE Class 9 || Physics || Sound || Animation || in English sreducators.com
SoundAt the end of this lesson, you will learn:
The production of sound
The characteristics of sound waves
The reflection of sound
The definition of echo and reverberation
The structure of the human ear
The explanation of sauna and its description
Sound is a sensation or a feeling that we hear. It is produced by a vibrating object, and the motion of materials or objects causes vibrations.
Sound is created by the vibration of particles, and it requires a medium such as air, liquid, or solid. But, how can we prove that it needs a medium to travel?
Sound waves are longitudinal waves, a wave in which the particles of the medium vibrate back and forth in the same direction the wave is moving. The faster the sound source vibrates, the higher the frequency. Higher frequencies are interpreted as a higher pitch.
The speed of sound is defined as the distance with which a point on a wave, such as a compression or a rarefaction, travels per unit time. The speed of sound depends on the material through which it's passing; it is greater in solids than in liquids or gases.
The sensation of sound persists in our brain for about 0.1 seconds to hear a distinct echo.
Structure of the Human Ear
The human ear consists of three parts: the outer ear, the middle ear, and the inner ear.
The outer ear is the visible part of the ear and collects sound waves from the surrounding area.
The middle ear contains the eardrum and three small bones that transmit the vibrations to the inner ear.
The inner ear contains the cochlea, which is responsible for converting sound vibrations into electrical signals that the brain can interpret.
Sauna
Sauna is a small room or a building designed to experience dry or wet heat sessions, which can be relaxing and rejuvenating for the body.
The hearing range of the average person is between 20 hertz and 20,000 hertz. Animals like whales and elephants produce sounds in the infrasound range while frequencies higher than 20 kilohertz are called ultrasonic sound or ultrasound. Some dogs can hear ultrasound.
Sonar is a device that uses ultrasonic waves to measure the distance, direction, and speed of underwater objects. The word sonar stands for sound navigation and ranging. Sonar consists of a transmitter and a detector and is installed in a boat or a ship. These waves travel through the water and after striking the object on the seabed, get reflected back and are sensed by the detector. The distance of the object that reflected the sound wave can be calculated using echo-ranging method.
Sound is produced due to the vibration of different objects. Sound travels as a longitudinal wave through a material medium. It travels as successive compressions and rarefactions in the medium. The speed of sound depends primarily on the nature and temperature of the transmitting medium. Soundwaves with frequencies below the audible range are called infrasonic.
Ultrasonic or ultrasound has many medical and industrial applications.