A sound is produced due to a vibration. When the vibrations travel through air or another medium and reach our ears, we hear it as sound.
Human beings produced sounds from their voice box - also known as the larynx - which is located at the upper end of the windpipe.
It has two vocal cords which are stretched across, leaving a narrow slit between them for the passage of air. These vocal cords are also called vocal folds.
During normal breathing, the vocal chords are held apart and no sound is produced.
When we want to speak or make a sound, we send air from our lungs towards the voice box. This air causes the vocal chords to vibrate. When the vocal chords vibrate, they open and close alternately, trapping the air and then releasing it. Each release sends a little puff of air which produces the sound.
The eardrum is a thin, tightly stretched membrane which transmits the vibrations coming through the outer ear to the inner ear.
The three musical instruments which produce sound by vibrating strings are:
No, sound cannot travel on the moon because there is no atmosphere on the moon and sound cannot travel through vacuum. Sound needs a medium to propagate.
Vacuum does not contain any particles of matter. Since sound is propagated by the vibration of particles, it cannot travel through vacuum.
The to and fro motion of an object about its mean position is called vibration or oscillatory motion. Examples of oscillatory motion are a child on a swing or vibration of a guitar string.
The vibrating parts of the given instruments are:
• Veena Stretched string
• Tabla Stretched membrane
• Drum Stretched membrane
• Guitar Stretched string
• Sitar Stretched string
• Dholak Stretched membrane
• Flute Air column
• Mridangam Stretched membrane
Putting objects into the ear pushes earwax further back into the ear canal, where it's more likely to become impacted. Sharp objects can also damage the eardrum and it is thus not advisable to put sharp objects in our ears.
Light travels with a greater speed compared to the speed of sound. Hence, we see a flash of lightning before we hear the sound of thunder.
Sound can travel through all the mediums listed, whether they are solids, liquids or gases. Sound does not travel through a vacuum.
A woman’s voice is generally shriller because females have shorter vocal folds, which produce higher frequency sounds.
The maximum displacement of a vibrating object from its mean position is called its amplitude.
The time taken by a vibrating object to complete one vibration cycle or oscillation is called the time period of the vibration or time period of oscillation.
The number of oscillations made by a vibrating object in one second is called its frequency.
The shrillness of a sound is called its pitch. It depends on the frequency of vibration.
Sound produced by a bee and a lion are different because they have different pitch and loudness. The sound produced by a bee is feeble (low amplitude) and high pitched (high frequency) whereas the roar of a lion is loud (high amplitude) but low pitched (low frequency).
Loudness is proportional to the square of the amplitude. This means that if amplitude is doubled, loudness increases four times. If amplitude is increased three times loudness will increase by nine times.
Sounds lying in the frequency range of 20 Hz to 20,000 Hz are considered audible to human beings. Any sound lying outside this frequency range is inaudible to us. Sounds with frequency less than 20 Hz are called infrasonic sounds while sounds with a frequency greater than 20,000 Hz are called ultrasonic.
Infrasonic is any sound that has a frequency below the human capability of hearing, i.e. below 20Hz. Ultrasonic sound is, conversely, a sound with frequency that is above the human hearing range, or over 20,000Hz.
The difference between noise and music is perceived differently by different people. Unpleasant sounds are called noise while pleasing sounds are called music. But, if a musical sound becomes too loud, it can be turn out to be noise.
Sources of noise pollution are:
(a) Construction work
(b) Vehicles on road
(c) Fire crackers
(d) Sound from loudspeakers
(e) Television at very high volumes
(f) Music concerts
Noise pollution can have a very bad effect on our health. Prolonged exposure to loud noises can damage the ear drums, causing hearing impairment or hearing loss.
More than just hearing damage, the stress of noise pollution can lead to sleepless nights, anxiety, and high blood pressure and even increased chances of heart trouble.
She should buy the house which is away from the market in order to avoid exposure to excessive noise and noise pollution and live in a comparatively peaceful place.
The presence of noise in the environment is called noise pollution.
Noise pollution can be reduced by:
• Use of strong and effective silencers in vehicles
• Trees plantation on the roadside and around buildings in residential areas
• Locating Industries away from residential areas
• Reducing the use of car horns
• TV and music systems at low volumes
Loudness of sound is directly proportional to the square of the amplitude of the vibration producing the sound. In other words, if the amplitude doubles, the loudness increases by a factor of four.
The pitch of a sound is proportional to its frequency. As the frequency of vibration increases, the pitch of the sound also increases. A sound is said to be high pitched if its frequency of vibration is high, and is low pitched if it has a small frequency of vibration.
Loudness of the sound depends upon the amplitude whereas pitch depends upon the frequency.
Since the sound is getting louder and louder, it means there is a change in the amplitude while the frequency remains constant.
When we strike the glass lightly, the amplitude of vibrations is small and hence the sound produced is also feeble. But when hit harder, the amplitude is large, which produces a louder sound.