Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
1-19 The material through which sound waves travel is called the medium. The density of the medium determines the ease, distance, and speed of sound transmission. The higher the density of the medium, the slower sound travels through it. The detector acts as the receiver of the sound wave. Because it does not surround the source of the sound wave, the detector absorbs only part of the energy from the wave and sometimes requires an amplifier to boost the weak signal. As an illustration of what happens if one of these three elements is not present, let’s refer to our experiment in which a bell was placed in a jar containing a vacuum. You could see the bell being struck, but you could hear no sound because there was no medium to transmit sound from the bell to you. Now let’s look at another example in which the third element, the detector, is missing. You see a source (such as an explosion) apparently producing a sound, and you know the medium (air) is present, but you are too far away to hear the noise. Thus, as far as you are concerned, there is no detector and, therefore, no sound. We must assume, then, that sound can exist only when a source transmits sound through a medium, which passes it to a detector. Therefore, in the absence of any one of the basic elements (source, medium, detector) there can be NO sound. Q18.   Sound waves transmitted from a source are sometimes weak when they reach the detector. What instrument is needed to boost the weak signal? TERMS USED IN SOUND WAVES Sound waves vary in length according to their frequency. A sound having a long wavelength is heard at a low pitch (low frequency); one with a short wavelength is heard at a high pitch (high frequency). A complete wavelength is called a cycle. The distance from one point on a wave to the corresponding point on the next wave is a wavelength. The number of cycles per second (hertz) is the frequency of the sound. The frequency of a sound wave is also the number of vibrations per second produced by the sound source. Q19.   What are the three basic requirements for sound? CHARACTERISTICS OF SOUND Sound waves travel at great distances in a very short time, but as the distance increases the waves tend to spread out. As the sound waves spread out, their energy simultaneously spreads through an increasingly larger area. Thus, the wave energy becomes weaker as the distance from the source is increased. Sounds may be broadly classified into two general groups. One group is NOISE, which includes sounds such as the pounding of a hammer or the slamming of a door. The other group is musical sounds, or TONES. The distinction between noise and tone is based on the regularity of the vibrations, the degree of damping, and the ability of the ear to recognize components having a musical sequence. You can best understand the physical difference between these kinds of sound by comparing the waveshape of a musical note, depicted in view A of figure 1-13, with the waveshape of noise, shown in view B. You can see by the comparison of the two waveshapes, that noise makes a very irregular and haphazard curve and a musical note makes a uniform and regular curve.

Electrical News
The Risks & Rewards of Early Tapeout
Verification remains a key issue in system-on-chip development. The time...
Nikola Tesla, Vincent Van Gogh & the Second Renaissance
Tesla was alive at the same time as Vincent! Both...
Future of PCM: Optoelectronic?
Work by a team at the University of Oxford and...
Mobile Uptick Ahead, Says ARM
Mobile device shipments are rebounding from a slump, but challenges...
EEVblog #643 – Mailbag
Mailbag Monday Spoilers: Dual voltage source selection circuit Casio FX-7000G...
Nvidia Raises Android Gaming Ante
The Nvidia Tegra K1 inside the Xaomi MiPad and now...
Learn Signal Integrity Online
Signal-integrity evangelist Eric Bogatin's classes are now available through an...
25G Ethernet on Tap at IEEE
In the wake of a June launch for an industry...
NAND Suit: Toshiba Seeks $1.1B From SK Hynix
South Korea's SK Hynix Inc. disclosed in a regulatory filing...
Cloud-Based Chip Design Research & Education
Semiconductor Research and Silicon Cloud give chip designers global reach....
Is Your Processor IP ISO 26262-Compliant?
With the growth in ADAS and the growing demand for...
NI's System-on-Module Technology Aims to Reshape Embedded Market
National Instruments has just released a complete middleware solution for...
XMOS Sees Key $26M Investment
UK chip designer XMOS has raised $26.2m from three global...
VC Investments Spike in Q2
US companies posted double-digit increases in second-quarter investments from a...
5G Calling: US Answers, Sorta
In the third and final part of our series on...
Engineers Should Study Finance: 5 Reasons Why
Engineers make design decisions that affect the company bottom line,...
EEVblog #642 – TI Connected Launchpad
Dave checks out the $20 TI EK-TM4C1294XL Tiva C Series...
MIT Wrist-Robot Adds Extra Fingers
The Massachusetts Institute of Technology (MIT) has created a wrist-worn...
OCZ Updates SQL Flash Accelerator
Toshiba-owned company makes flash acceleration simple for SQ L DBAs...
Micro Python Preps for Mass Production
Micro Python is priming the presses. After smashing its Kickstarter...

Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +