Analog and Digital Formats - Essay Example

There are two types of telecommunication transmission, analog transmission and digital transmission. When we say analog the “ transmission uses signals that are exact replicas of a sound wave or picture being transmitted” ( thinkquest.org ). For example, a pattern of heartbeat is seen on the ECG machine which can be interpreted visually by a doctor. The original music sound is considered an analog. However, when it comes to encoding sound or music, the digital transmission is used nowadays.

The main reason is explained by Smith ( 1999 ) in the book Why Digitize? Smith asserts that :.. flexibility is one of the chief assets of digital information.  The bits of data can be recombined for easy manipulation and compressed for storage. Digital images will not degrade when copied as analog formats degenerate. Information in digital formats can over access and can be downloaded millions of times. The process of converting analog to digital format is known as “digitization”. It is also important to note that digital format is best used with electronic communication such as PCs, Ipods , DVD players, and other electronic equipment.

The main function of digital recording is the conversion of the analog wave into a stream of numbers and records the numbers instead of a wave. Usually, a device known as analog-to-digital converter (ADC) does the conversion. However, a multimedia PC can also perform the conversion by using audio editing software. There are many formats that you can choose from such as Windows WAVE (.wav) ,QuickTime Movies (.mov), RealAudio (.ra, .ram, .rp),MPEG Audio (.mpg) Moving Picture Experts Group MIDI (mid) Muscial Instrument Digital Interface, and Windows Media Audio (.wma). The choice of format determines delivery speeds, quality of sound, plug-ins required and size of the audio file.

The quality of sound is affected by the sampling rate especially in analog-to-digital conversion. Certain distortions such as noise can happen if the sampling rate is not achieved. The website pctechguide suggests that ideal sampling rate in audio recording for personal use is 44.1 kHz .Due to the different formats available, some players cannot recognize the format, thus, programs like “codec’ can make this possible. There are many types of codec such as divx codec, avi codec, MPEG-Layer 3 codec depending on the user’s needs and preference.

An important factor in converting analog to digital formats is compression. Compression enables your files to download quickly. Compression has two characteristics: lossless and lossy compression. These two features differ in the ability to recover original data when a file is uncompressed. When uncompressing important information where data loss should not happen, lossless compression is used as in the case of financial spreadsheets. On the other hand, lossy compression is commonly used in video or audio since certain loss of information cannot be detected by ordinary users.

Finally, to be able to listen to music in an Ipod, the digital signal is then converted by an analog-to-digital converter. Usually, a Digital Signal Processor ( DSP ) performs the conversion by decoding the digital file from the memory ( during playback ) and converting it to analog by passing it through the digital-to-analog converter. When this happens, one enjoys the pleasure of listening to his favorite music.WORKS CITED :PC techguide. Sampling Rate. Retrieved from http://www.pctechguide.

com /glossary/WordFind. php?wordInput=Sampling on April 3,2009.Smith, Abby (1999 ) Why Digitize? Council on Library and Information Resources. Retrieved from http://www.clir.org/pubs/reports/pub80-smith/pub80.html on April 8, 2009.Through the wires. Analog and Digital signals . Retrieved from http://library.thinkquest.org /27887/gather /fundamentals /analog_and_ digital.shtml on April 5, 2009.