Browse
Search
Agenda - 06-27-1983
OrangeCountyNC
>
Board of County Commissioners
>
BOCC Agendas
>
1980's
>
1983
>
Agenda - 06-27-1983
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
4/24/2017 8:06:06 AM
Creation date
4/18/2017 2:53:37 PM
Metadata
Fields
Template:
BOCC
Date
6/27/1983
Meeting Type
Regular Meeting
Document Type
Agenda
Document Relationships
Minutes - 19830627
(Linked From)
Path:
\Board of County Commissioners\Minutes - Approved\1980's\1983
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
97
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
View images
View plain text
Frequency 0 <br /> Frequency is the time rate of repetition of a periodic phenomenon . <br /> The traditional unit for frequency in the United States was at one time <br /> "cycles per second ." Now, we use "Hertz ," abbreviated "Hz ." Only the <br /> name has changed; the meaning hasn ' t . <br /> To represent the total noise of any source , acousticians break the <br /> 1 <br /> noise into frequency components . In other words , tiow much is <br /> low-frequency noise , how much is middle-frequency noise ) how much is <br /> high-frequency noise? This breakdown is essential to any comprehensive <br /> study of a noise problem for two reasons : <br /> ▪ People react differently to low-frequency and high-frequency <br /> noise , because high-frequency noise is much more disturbing. It <br /> is also more capable of producing hearing lossl. <br /> . Engineering solutions to a noise problem are different for <br /> different frequencies . (Low-frequency noise is generally harder <br /> to control . ) <br /> The frequency distribution of a noise is determined by passing the <br /> noise successively through several different filters that eparate the <br /> noise into 8 or 9 octaves on a given frequency scale . Just like an <br /> octave on the piano keyboard of Fig. 3 , an octave in sound analysis <br /> represents the frequency interval between a given frequencylr, such as 300 <br /> Hz , and twice that frequency , which for 300 Hz would be 600 Hz. <br /> 2 OCTAVES <br /> ABOVE <br /> MIDDLE C MIDDLE C <br /> luleil 111111 <br /> 261.6 Hz 1046 4 Hz <br /> L <br /> 125 250 500 1000 2000 4000 <br /> OCTAVE BAND CENTER FREQUENCY (Hz) <br /> FIG. 3. PIANO KEYBOARD OCTAVE. <br /> 10 <br /> 01.tftyrr Sfrrr:$ st' " • • <br />
The URL can be used to link to this page
Your browser does not support the video tag.