SOUND
Sound is a physical entity, unlike noise which is the perception of sound. Sound is a travelling wave which is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations
Sound is a physical entity, unlike noise which is the perception of sound. Sound is a travelling wave which is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations
Sound is produced by vibrating bodies. By vibrating a body, compressions and rarefactions are produced in the air. The molecules of air vibrate in the direction of wave, hence sound is compressional wave.
HUMAN EAR
The human ear consists of three sections: the outer ear, the middle ear, and the inner ear.
The outer ear includes the auricle (pinna), the visible part of the ear that is attached to the side of the head, and the waxy, dirt-trapping auditory canal. The tympanic membrane (eardrum) separates the external ear from the middle ear, an air-filled cavity. Bridging this cavity are three small bones—the malleus (hammer), the incus (anvil), and the stapes (stirrup). The cochlea and semicircular canals make up the inner ear.
Loudness of sound is a characteristic of sound by which a loud and a faint sound can be distinguished. Loudness not only depends upon the intensity of sound but also on physical condition of ear. Loudness also depends upon amplitude and area of vibrating body.
Amplitude: Amplitude of vibrating body is large, the sound produced will be loud while the sound will be low if amplitude of vibrating body is small.
Area: Larger the area of surface of vibrating body, louder is the sound and vice versa.
Distance: greater the distance, fainter would be voice.
INTENSITY
The intensity of sound, at a given distance, depends upon the amplitude of the waves. Sound energy flowing per second through a unit area held perpendicular to the direction of sound waves is called the intensity of sound. Intensity of sound is a physical quantity and does not depend on the condition and sensitiveness of the ear. Sound level is measured in decibels. A scale for measuring intensity level of sound is called decibel scale
PITCH
The characteristic of sound by which a shrill voice can be distinguished from a grave one is called pitch of sound.
The characteristic of sound by which a shrill voice can be distinguished from a grave one is called pitch of sound.
QUALITY OF SOUND
The characteristic of sound by which two sounds of same loudness and pitch can be distinguished from each other is called quality of sound.
The characteristic of sound by which two sounds of same loudness and pitch can be distinguished from each other is called quality of sound.
ULTRASONICS
Sounds of frequency greater than 20,000Hz which are inaudible to human ear are called ultrasonics. In medical ultrasonic waves are being used to diagnose and treat different ailment. They are also used to measure depth of ocean and find out cracks in high speed moving bodies
Bats use a variety of ultrasonic ranging (echolocation) techniques to detect their prey. They can detect frequencies as high as 100 kHz, although there is some disagreement on the upper limit.
Dogs can hear sound at higher frequencies than humans can. A dog whistle exploits this by emitting a high frequency sound to call to a dog. Many dog whistles emit sound in the upper audible range of humans, but some, such as the silent whistle, emit ultrasound at a frequency in the range of 18 kHz to 22 kHz
Sounds of frequency greater than 20,000Hz which are inaudible to human ear are called ultrasonics. In medical ultrasonic waves are being used to diagnose and treat different ailment. They are also used to measure depth of ocean and find out cracks in high speed moving bodies
Bats use a variety of ultrasonic ranging (echolocation) techniques to detect their prey. They can detect frequencies as high as 100 kHz, although there is some disagreement on the upper limit.
Dogs can hear sound at higher frequencies than humans can. A dog whistle exploits this by emitting a high frequency sound to call to a dog. Many dog whistles emit sound in the upper audible range of humans, but some, such as the silent whistle, emit ultrasound at a frequency in the range of 18 kHz to 22 kHz
