The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
Have you ever used a guitar, drum, or violin as a musical instrument? You hear a vibration as you touch the strings of a guitar. The same for a drum, we hear a ‘thump’ sound as we strike a drum. Indeed, how can one instrument produce a wide range of sounds? How does this occur? What is the sound? How do we create sound? How is sound produced and how is production and propagation of soundachieved?
A sound, much like electricity, heat, or light, is a source of energy. Let’s analyze a few sound sources, including a whistle. It makes a loud ringing noise as you hit a button. Now, instead of just listening to the alarm, once you have reached it, put your finger on the bell. Are you able to feel it vibrating? It’s the secret to the sound here. For guitars and drums, it’s much more apparent. Any time you pluck it, you can see the wires vibrating. The echo often ceases when the bell or the guitar stops vibrating. Vibration is called the to and fro motion of the body.
Characteristics of Sound Wave
A continuous succession of peaks and valleys is pictorially represented by tone. The difference is called the wavelength of the wave or the time between two successive peaks or troughs. The number of cycles per unit time is referred to as the tone frequency. Frequency is measured in per second or Hertz intervals.
The more an entity vibrates, that is, the higher the frequency, the greater the sound pitch. The distinction between the voice of a man and that of a woman must be obvious to you. A man’s voice has a lower frequency that adds to the bass’s deepness in the voice. Men, on the other hand, have a higher-frequency sound that results in greater shrillness or pitch.
A sound wave’s speed is determined by the type of medium by which it passes. In solids, sound waves move the fastest regardless of the proximity of molecules. Similarly, in gases, sound waves propagate steadily when gases are spaced far away from each other. The condition of the medium through which sound passes is not the only aspect determining the velocity of a sound. The density, temperature, and elasticity of the medium in which sound waves pass will also influence the speed of a sound wave.
The sound that a guitar produces is different from the sound that a drum produces. This is because different characteristics are found in the sound produced by different sources. The pitch, wavelength, and amplitude will describe sound.
A sound wave frequency is defined as the number of rarefactions and compressions occurring per unit of time. The frequency formula for a wave is given as:
The distance is defined as the wavelength of a sound wave between the successive compression and rarefaction. The sound formula’s wavelength is given as follows:
In a sound wave, the sound amplitude is the frequency of the highest disturbance. A measure of energy is also the amplitude. The larger the amplitude, the greater the energy of a sound wave.
Reflection of sound is akin to the reflection of light. The reflection of sound complies with the following principles of reflection.
It is transmitted back to its origins as a sound strikes a rough surface. This sound reflection is otherwise known as an echo. Although soft surfaces absorb sound and quiet it, hard surfaces appear to reflect sound. If the sound wave is low in pitch, so the sound wave will not be reflected. Often, if the environment is wide and has several reflective surfaces, such as valleys and vast empty spaces, we hear multiple reflections from a sound source. This phenomena is referred to as reverberation. A principle in working of sonar.
Sounds ranging from 20 Hz to 20 kHz can be detected by human beings. Sounds of frequencies above the human hearing spectrum are referred to as ultrasound, and are widely used in sonar. Infrasound is the name of sounds with frequencies outside the human ear structure and working capacity. The typical sound produced by human speech has frequencies of between 100 and 1,000 H
This chapter taught us the basics of sound. We learned about the types, reflection and frequency of sound. We can use this knowledge and understand the infrasonic and ultrasonic waves and working of sonar.
1. What does sound mean?
Mechanical radiant energy that is emitted in a material medium (such as air) by longitudinal pressure waves and is the objective source of hearing.
2. What is sound class 9th?
Sound is a form of energy that in our ears creates a sense of hearing . Due to the vibration of objects, sound is produced.
3. What are the 5 characteristics of sound?
Sound waves have five major characteristics: wavelength, amplitude, frequency, period of time, and velocity.
4. What are 4 properties of sound?
Pitch, intensity (loudness), duration, and timbre are the four properties of sound.
5. What are the two key features of sound?
Frequency, velocity and amplitude are what they are. Pitch and loudness, two of the major sound features.