Quantcast CHARACTERISTICS OF SOUND

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
MEMS Spurred by Industrial IoT
Industrial uses of microelectromechanical systems (MEMS) still trail consumer ones...
eetimes.com
Tablets for Patients: Pilot Programs Demonstrate Benefits
Patients who use tablets to access to their own care...
eetimes.com
Get Your Kicks at DFT Boot Camp
Engineers at Mentor Graphics provide an introduction to design-for test...
eetimes.com
WiFi to Switch on IoT Appliances
Electrolux says it is one of several white good makers...
eetimes.com
A CTO's View of Comms 2015
Ethernet has a growing role in automotive and industrial networks...
eetimes.com
Become a Measurement Master
Becoming a measurement master, like anything else, takes time and...
eetimes.com
Ten Flash Drives That Will Turn Heads (and Store Your Data!)
Today's flash drives have come a long way with iconic...
eetimes.com
10 Tech Gifts to Buy Your Engineer for Christmas
Here is a list of last minute ideas for making...
eetimes.com
Holiday Movies to Geek Out About
EE Times wants to ensure domestic bliss with a handy...
eetimes.com
Road to Auto Market Paved With Fault-Tolerant SoCs
Data protection and redundancy features implemented across entire SoC designs...
eetimes.com
Boston-Area Engineers to Share Expertise at ESC Boston 2015
In an exciting new session format at ESC Boston 2015,...
eetimes.com
Memory Design Trends in 2014
Memory transitions, increased-density drive design trends: Customers are looking for...
eetimes.com
True 3-D Chips Harness Nanotubes
Stanford University has learned how to stack any number of...
eetimes.com
Top 15 Analog, MEMS & Sensors News From 2014
From faulty MEMS mics to NXP's labor disputes, here are...
eetimes.com
Space Weather Satellite Set for Launch
NOAA's Deep Space Climate Observatory will serve as an early...
eetimes.com
Hackers Go Off-Grid for Power
Hackathon produces designs that could be assembled by villagers with...
eetimes.com
Ten Hot & Cool NASA Innovations
Partnering with industry, NASA has developed new technologies that are...
eetimes.com
The Circle – The Future's Imperfect in the Present Tense
Dystopian novel satirizes mega-Google companies and the modern techie ethos....
eetimes.com
Friday Quiz: S-Parameters
S-Parameters are no longer just for microwave engineers. High-speed digital...
eetimes.com
EEVblog #694 – Mailbag
Mailbag that’s not on a Monday, because Dave has been...
eevblog.com
 


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 +