MUS 570 / CSC 570
file size for ONE MINUTE of sound
(1 floppy = 1.44 MB)
(1 CD-R = 700 MB)
|44,100 Hz||2.5 MB||5.1 MB||5.1 MB||10.3 MB|
|22,050 Hz||1.2 MB||2.5 MB||2.5 MB||5.1 MB|
|11,025 Hz||646 kb||1.2 MB||1.2 MB||2.5 MB|
|8,000 Hz||469 kb||938 kb||938 kb||1.8 MB|
FREQUENCY--Measured in Hertz (Hz), vibrations per second that determine pitch. For example, the orchestral tuning note, A440 = 400 vibrations per second, sounding the pitch of "A."
FREQUENCY RANGE (of human hearing)--A sound must have a frequency of roughly 20 Hz or more on the low end to be heard. On the high end, young ears can hear frequencies of up to 17,000 Hz (17 kHz) or more. Older folks are doing well to hear 12 kHz frequencies.
HERTZ (Hz)--The unit of measurement of frequency equal to one cycle of a periodic waveform per second (in English ... vibrations per second ;-). (K = thousand. 3 kHz = 3,000 Hz)
IMA--Interactive Multimedia Association file format which has a 4-to-1 compression ratio.
LEVEL METERS / VU (Volume Unit) METERS--Visual meters that indicate the volume levels of incoming and outgoing audio signals.
MIDI--Musical Instrument Digital Interface, a standardized protocol for communication between electronic devices and computers. File extension is .mid
MIDI TIME CODE (MTC)--A
MINIPLUG--A 1/8" phone plug (stereo or mono).
MOV--Apple's QuickTime file format, a common multimedia player.
.MP3--technically, "MP3-1 Audio Layer 3," as so-dubbed by the Motion Picture Experts Group (MPEG). The short answer is that MP3 is a file compression technique that reduces sound files to about one-tenth of their original size. All the sounds are stored as numbers. MP3 removes any numbers representing sounds beyond the range of human hearing. While MP3 files aren't "exactly" the same quality as a CD audio file, they come pretty close.
MULTITRACK RECORDING--Recording sounds on individual tracks that all play back at the same time (unless muted).
MUTE--A switch or control that zeroes out or turns off the audio from a specified track.
NYQUIST THEOREM--Signals with frequencies up to a little less than half the sample rate can be sampled without distortion. That is, the sampling rate must be at least twice the number of cycles of vibration per second of the highest recorded frequency in order to accurately represent the sound without distortion. The Nyquist Frequency is that magic sampling frequency where one can sample without distortion.
PAN--The placement of sound left-to-right in the stereo field.
PINK NOISE--See Noise, Pink.
PUNCH IN--Selecting a specified area in which to record or re-record.
REVERB--An audio effect that adds a spacious, echo-like character to a sound.
RM or RAM--Real Audio Media file format used by RealNetworks, one of the most commonly found streaming technologies on the web.
RMF--Rich Music Format developed by Beatnik; similar to MIDI files.
SPECTRAL VIEW--The alternate view of waveform data, as compared to waveform view. This mode is helpful for spotting prevalent frequencies via color. Brighter colors represent greater amplitudes. Dark blue represents virtually no amplitude components within a frequency range. Bright yellow represents higher-amplitude frequencies. Lower frequencies appear near the bottom of the window, and higher frequencies are displayed from the middle-to-top part of the scale.
SMPTE TIME CODE--Developed by the Society of Motion Picture & Television Engineers (SMPTE), this is the standard digital code used to synchronize sight and sound.
TRACK--A channel on a tape recorder, sequencer or other recording device; one of a set of concentric circles on a floppy disk.
.WAV--The audio format for the Windows operating system, which has become the standard for sampled audio on the web. .WAV encodes sound using Pulse Code Modulation (PCM), a process that digitizes the analog sound wave by sampling it a certain number of times per second and storing each sample as an 8-bit or 16-bit "word" (bit depth). The higher the sample rate and bit depth, the more accurate is the sound reproduction. On the down side, .wav files tend to be large. Audio CD resolution is 16-bit, stereo, 44.1 kHz. Web audio can be as low as 8-bit, 8 kHz.
WHITE NOISE--See Noise, White.
.WMA--Windows Media Audio file, developed by Microsoft. Like MP3 files, WMA files compress information. WMA files also have the ability to program the file so it cannot be copied. WMA file sizes can be significantly smaller than even the compressed MP3 files.