Sound viii

Anything that moves back and forth makes sound. Moving back and forth is called vibrating. Pluck a guitar string and watch it vibrate back and forth. The vibrations make sound waves.

Anything that moves back and forth makes sound. Moving back and forth is called vibrating. Pluck a guitar string and watch it vibrate back and forth. The vibrations make sound waves.

Sound waves are a lot like Sound waves are a lot like water waves. If you throw a water waves. If you throw a pebble in a lake or pond, pebble in a lake or pond, you can see the waves you can see the waves move out in circles. Sound move out in circles. Sound waves move out in circles waves move out in circles from whatever is vibrating.from whatever is vibrating.

Musical Instruments &their Vibrating Parts

MUSICAL INSTRUMENTS

1. Veena

2. Tabla

3. Flute

4. Drum

5. Guitar

6. Trumpet

7. Cymbals

8. Noot

VIBRATING PARTS PRODUCING SOUNDS

Stretched string Stretched membrane Air-column … …. …. …. ….

Sound Produced by HumanSound Produced by Human

In the human larynx, two pairs of vocal cords are present. They are made of elastic connective tissue covered by folds of mucous membrane. One pair, the false vocal cords, extends from the epiglottis to the angle of the thyroid cartilage; these cords narrow the glottis (the pharyngeal opening of the larynx) during swallowing. Below the false cords are the true vocal cords, extending from the arytenoid cartilages to the angle of the thyroid cartilage. Vibration of this pair of cords by air passing out of the lungs causes the formation of sounds that are amplified by the resonating nature of the voice box.

Anything that moves back and forth makes sound. Moving back and forth is called vibrating. Pluck a guitar string and watch it vibrate back and forth. The vibrations make sound waves.

Sound is produced when something vibrates. The vibrating body causes the medium (water, air, etc.) around it to vibrate. Vibrations in air are called traveling longitudinal waves, which we can hear.

Any simple sound, such as a musical note, may be completely described by specifying three perceptual characteristics: pitch, loudness (or intensity), and quality (or timbre). These characteristics correspond exactly to three physical characteristics: frequency, amplitude, and harmonic constitution, or waveform, respectively. Noise is a complex sound, a mixture of many different frequencies or notes not harmonically related.

If a string that is fixed on both ends is bowed or plucked, such as in a violin, vibrations are formed that are in a standing wave pattern, having nodes at the fixed ends, and an antinode in the center. Several harmonics are also produced, in a similar way to the standing wave.

You have an ear on each side of your head. Your ears let you hear sounds. You can hear music and other nice sounds. You can hear sirens and other warning sounds.

The human ear is divided into three parts: the outer ear, the middle ear, and the inner ear. The outer ear includes the visible part of the ear that is attached to the side of the head and the ear canal. The eardrum separates the outer ear from the middle ear, which is an air-filled cavity. Inside this cavity are tiny bones that vibrate when sound waves pass through them. These bones help send sound into the inner ear. The inner ear contains an organ that helps you keep your balance and another organ that passes sound waves to the brain.

Sound, physical phenomenon that stimulates the sense of hearing. In humans, hearing takes place whenever vibrations of frequencies from 15 hertz to about 20,000 hertz reach the inner ear. The hertz (Hz) is a unit of frequency equaling one vibration or cycle per second. Such vibrations reach the inner ear when they are transmitted through air. The speed of sound varies, but at sea level it travels through cool, dry air at about 1,190 km/h (740 mph). The term sound is sometimes restricted to such airborne vibrational waves. Modern physicists,

OSCILLATION

Oscillation is the repeated motion back and forth past a central neutral position, or position of equilibrium. A single motion from one extreme position to the other and back, passing through the neutral position twice, is called a cycle.

FREQUENCY

• The number of cycles per second, or hertz

(Hz), is known as the frequency of the oscillation.

The amplitude of a sound wave is the degree of motion of air molecules within the wave, which corresponds to the changes in air pressure that accompany the wave. The greater the amplitude of the wave, the harder the molecules strike the eardrum and the louder the sound that is perceived.

PITCH

Pitch (music), highness or lowness of a musical tone as determined by the rapidity of the vibrations producing it.The frequency determines the shrillness or pitch of a sound.

LOUDNESS

The loudness or intensity of a noise is measured in a unit called the decibel. The softest audible sound to humans is 0 decibels, while painful sounds are those that rise above 140 decibels.

• Loudness of sound depends on its amplitude. It is proportional to the square of the amplitude of the vibration producing the sound.

NOISE AND MUSIC

At its simplest, music consists of a short, unaccompanied melody, known as monophony. But even the simplest melody consists of many important components. Some of the most obvious of these are the varying heights or pitches of the tones, their durations, their loudnesses, their tone colors or timbres, and their articulations.

MUSIC

Music can be happy, sad, romantic, sleepy, spine-tingling, healing—all kinds of things. But what is it? Some people define it as an artful arrangement of sounds across time. Our ears interpret these sounds as loud or soft, high or low, rapid and short, or slow and smooth. The sounds need to continue for a time in some sort of pattern to become music.

MUSIC

Music, artful arrangement of sounds across time. This definition is obviously very broad, but a narrower one would exclude too much. Music is part of virtually every culture on Earth, but it varies widely among cultures in style and structure.

NOISENOISE

Noise is a complex sound, a mixture of many different frequencies or notes not harmonically related.

NOISE POLLUTION

• Sounds of vehicles• Explosions • Bursting of crackers• Machines• Loudspeakers• Factories• --------• -------• ------

HARMS OF NOISE POLLUTION

• Lack of sleep

• Hypertension

• Anxiety

• Imparting of hearing

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• USE OF SILENCING DEVICES IN VECHILES

• RUN TV & MUSIC SYSTEM AT LOW VOLUME

• PLANTATION OF TREES.