Nyquist's LawAlso called Nyquist's Theorem. Before sound as acoustic energy can be manipulated on a computer, it must first be converted to electrical energy (using a transducer such as a microphone) and then transformed through an analog-to-digital converter into a digital representation. This is all accomplished by sampling the continuous input waveform a certain number of times per second. The more often a wave is sampled the more accurate the digital representation. Nyquist's Law, named in 1933 after scientist Harry Nyquist, states that a sound must be sampled at least twice its highest analog frequency in order to extract all of the information from the bandwidth and accurately represent the original acoustic energy. Sampling at slightly more than twice the frequency will make up for imprecisions in filters and other components used for the conversion.
For example, human hearing ranges from 20Hz to 20,000Hz, so to imprint sound to a CD, the frequency must be sampled at a rate of 40,000Hz to reproduce the 20,000Hz signal. The CD standard is to sample 44,100 times per second, or 44.1 kHz.
It's not just your lawnmower and household tools that your neighbor won't return. Our top picks include everything from updating device firmware... Read More »Interesting Times: Transformation in the IT Channel
Business transformation will remain the buzzword of the moment as channel firms continue to assess the direction of their companies in the age of... Read More »What is a Virtual Private network (VPN)?
Companies and organizations will use a VPN to communicate confidentially over a public network and to send voice, video or data. Read More »
From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »Network Fundamentals Study Guide
A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »Computer Architecture Study Guide
This Webopedia study guide describes the different parts of a computer system and their relations. Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »