The document discusses the physics of sound and acoustics. It covers how sound is produced through vibrations, the speed of sound in different mediums, properties of sound like pitch, frequency, loudness and intensity. It also summarizes the anatomy of the human ear and how we perceive sound. Musical instruments are described based on how they produce sound through vibrating strings, reeds, lips or air columns. Interference patterns between sounds and concepts like resonance, beats, timbre and noise are also covered at a high level.
Sound waves are produced by the vibration of material objects. A disturbance in the form of a longitudinal wave travels away from the vibrating source. High-pitched sounds are produced by sources vibrating at high frequency, while low-pitched sounds are produced by low-frequency sources Sound waves consist of traveling pulses of high-pressure zones, or compression, alternating with pulses of low-pressures zones, or rarefaction. Sound can travel through gases, liquids, and solid, but not through a vacuum.
a ppt on sound
includes- what is sound
production of sound
propagation of sound
characteristics of sound
reflection of sound
applications of reflection of sound
range of frequencies
ultrasound and its 8 usages
hope it helpful :D
Sound waves are produced by the vibration of material objects. A disturbance in the form of a longitudinal wave travels away from the vibrating source. High-pitched sounds are produced by sources vibrating at high frequency, while low-pitched sounds are produced by low-frequency sources Sound waves consist of traveling pulses of high-pressure zones, or compression, alternating with pulses of low-pressures zones, or rarefaction. Sound can travel through gases, liquids, and solid, but not through a vacuum.
a ppt on sound
includes- what is sound
production of sound
propagation of sound
characteristics of sound
reflection of sound
applications of reflection of sound
range of frequencies
ultrasound and its 8 usages
hope it helpful :D
It is a very useful ppt for studying students .I have made with very much hard work it will surely help you. I have made it with an attractive way and do not trust on me ,first see and you sill yourself like it.
18. Beats are formed by the interference if two waves of slightly different frequencies traveling in the same direction. In this case one beat occurs at T-2 where constructive interference is greatest. BEAT (continued)
Sound is a longitudinal wave, creating compression and rarefaction areas. Vibrating sources cause air molecules to vibrate, not move. Compression is an area of higher than normal air pressure and rarefaction is an area of lower than normal air pressure. Often easier to represent as a graph of pressure vs distance, which will look like a sine wave. (see p354 bottom). Wavelength, frequency, amplitude, and the mathematic relationships between them all hold. Pitch is often substituted for frequency in music references.
Speed of sound is highly affected by the temperature and the density of the medium. In general, the speed of sound is greater the more dense the medium is, although there are exceptions (lead < water). Speed of sound in air = (332 + 0.6T) m/s (at normal atmospheric pressure) T is temperature in celsius. Otto von Guericke 1654, did experiments with sound finding that the intensity of sound decreases as air is removed. Also found that sound travels through water. SOUND NEEDS A MATERIAL MEDIUM FOR ITS TRANSMISSION. IT WILL NOT TRAVEL IN A VACUUM.
Intensity of sound or loudness is difficult to measure because the amount of energy involved is small in comparison to other forms of energy and because the potential range of sound intensity is great. Intensity and intensity level on the decibel scale both decrease as the distance from the source increases. This is due to the energy spreading itself more and more thinly over increased area.
Measured in decibels, where 0 dB is the threshold of human hearing; 160 dB will destroy the eardrum instantly. Intensity measures Power per unit area; intensity levels (dB) is a nonlinear relationship measuring the difference between two intensities.
Humans respond to frequencies between 20 and 20,000 Hz (male speaking voice 120 Hz; female, 250 Hz). Infrasonic denotes frequencies of less than 20 Hz; Ultrasonic, greater than 20,000 Hz.
A concave reflector will focus sound the same as a mirror focuses light at a single point. The reflecctor collects the sound waves and converges them into a small area. Echoes are produced when sound is reflected by a hard surface such as a wall. Can only be heard by the human ear when the time interval b/w the echo and the original sound is greater than 0.1 s and the distance b/w the person and the reflecting surface is greater than 17 m. Other applications: parabolic microphone to pick up distant sounds; echo-sounder to measure depth of sea; sonar devices to locate submarines, monitor fetuses, etc; radar, similar to sonar, but uses radio waves instead of sound.
Acoustics in buildings. Reverberation occurs when the reflecting surface in less than 17 m away, the echo follows so closely behind the original sound that the original sound appears to be prolonged. Reverberation time is defined as the time required for sound to die away and become inaudible.
![All sounds are caused by vibrations ,[object Object],[object Object],[object Object],[object Object],[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)