Glossary |
A B C D E F G H I L M P Q R S T U W
A |
Sonic Foundry's ACID is a loop-based music creation tool. With loop arranging and editing, ACID gives musicians unprecedented creative flexibility.
Advanced SCSI Programming Interface (ASPI)
A standard SCSI software interface that acts as a liaison between host adapters and SCSI device drivers. ASPI enables host adapters and device drivers to share a single SCSI hardware interface.
A collection of music. SIREN refers to CDs as albums.
The original sound waveform, which can be converted into digital data or recreated from a digital file. CDs store information as digital data. SIREN converts the signal from digital to analog form so you can hear it.
The person or band who recorded the music file or CD. SIREN displays media information in the Media Library and in the properties Library Info tab.
B |
Refers to the EQ plug-in that is built in. Each frequency band has a width associated with it that determines the range of frequencies that are affected by the EQ. An EQ band with a wide bandwidth will affect a wider range of frequencies than one with a narrow bandwidth.
A bit is the most elementary unit in digital systems. Its value can only be 1 or 0, corresponding to a voltage in an electronic circuit. Bits are used to represent values in the binary numbering system. As an example, the 8-bit binary number 10011010 represents the unsigned value of 154 in the decimal system. In digital sampling, a binary number is used to store individual sound levels, called samples.
The number of bits used to represent a single sample. All CDs from your personal collection that work in CD players use a bit depth of 16-bit.
The amount of digital information being stored per second of audio. In general, the higher the bitrate, the better the sound quality, but the larger the file size. In SIREN, you can set the encode quality used to record music from CDs to .wma files to 64 Kbps (near CD quality), 96 Kbps (CD quality), or 128 Kbps (transparency). Set this option in the Preferences window General tab.
The raw number measurement of errors that occur as a CD player or CD-ROM drive reads a disc.
A viewer, known as a Web browser, for the World Wide Web. Netscape Navigator and Internet Explorer are browsers.
Occurs when data from the hard drive cannot be accessed as fast as the software attempts to write it to the CD. This is the most common problem when writing CDs and tends to render the CD unusable.
Refers to a set of 8 bits. An 8-bit sample requires one byte of memory to store, while a 16-bit sample takes two bytes of memory to store.
C |
The amount of data that can be recorded and replicated on a CD. Normal capacity of a CD is 74 minutes and 30 seconds of audio or 654.7 Megabytes (Mb).
Information that SIREN can retrieve about an audio CD if the CD itself does not include this information. You can save this information to a local database on your computer. SIREN automatically saves this information as you record audio tracks.
SIREN saves song information to this database for later retrieval when you add it manually or obtain it from CDDB. When you insert an audio CD, SIREN looks here first to find a match. If information for the CD does not exist in this database, SIREN looks in the cdplayer.ini file and the CD-TEXT on the CD itself. Set your preferences to enable SIREN to use this file.
Several Windows-based applications, including the Windows CD Player, use this file to store CD information. SIREN looks in this file for CD information if it is not available from the SIREN CD information database. When you add information manually or obtain it from CDDB, you can then save the information to this file so that it will be available to other applications. Set the preferences to enable SIREN to use this file.
Also known as a CD-ROM player. The CD-ROM drive is the hardware piece used to read data from a compact disc.
Refers to CD-ROM, CD-R, and CD-RW drives.
Some newer audio CDs embed song information as CD-TEXT. If SIREN cannot find the song information on either its local database, or the cdplayer.ini file, it attempts to retrieve it from the CD itself. If it finds this information, it stores it in a local database. Set your preferences to enable SIREN to use this file. Not all CD-ROM drives can read CD-TEXT information.
The clipboard is where data that you have cut or copied is stored. In SIREN, you can cut or copy text while in edit mode. You can then paste the data back into SIREN at a different location or paste it into other applications, such as Microsoft Word, or another instance of SIREN.
Clipping is what occurs when the amplitude of a sound is above the maximum allowed recording level. In digital systems, clipping is seen as a clamping of the data to a maximum value, such as 32,767 in 16-bit data. Clipping causes sound to distort. In SIREN, you can view the clip value in the Volume Panel.
An acronym for Coder/Decoder. Commonly used when working with data compression.
SIREN accesses the Compact Disc Database using an Internet connection. SIREN uses this database to obtain artist, album name, song titles, and other information for the selected CD and then displays that information.
Compact Disc-Digital Audio (CD-DA)
Generally known as a CD, the CD-DA can contain up to 74 minutes of stereo sound. Sound is converted into digital code by sampling sound waves at 44.1 kHz per second and converting each of these sound waves into a stream of 16-bit numbers. Other forms of compact discs (CD-ROM, CD-I and CD-R) all stem from the audio CD. The specification governing the audio CD is the Red Book standard.
Compact Disc-Read Only Memory (CD-ROM)
A compact disc format used to computer data but cannot be played on a music CD player. CD-ROM is a read-only format, to which no information can be written.
Compact Disc-Recordable (CD-R)
Also known as a CD-WO (Compact Disc-Write Once). The CD-R disc is the medium recorded onto when creating custom audio or data CDs. The CD-R disc has a much larger storage capacity than the floppy disk and, as a result, has become a very popular information storage medium.
Compact Disc-Recordable Music (CD-R Music)
Conforms to requirements specified in the SCMS. CD-R music discs contain a special code that indicates royalties have been paid per the 1992 Audio Home Recording Act.
Compact Disc-ReWritable (CD-RW)
An erasable medium used to record audio and other data with CD-RW drives.
A SIREN view that displays common controls for playing music and takes up little desktop space.
Method used to replace missing or damaged data with data that is similar in nature.
Constant Angular Velocity (CAV)
The speed at which the information track of a CD spins in relation to the reading laser. A CAV disc rotates at a constant number of revolutions per second. Data is read faster as the laser head reads toward the outer radii of the disc. The LP is a CAV system at 33-1/3 rpm.
Constant Linear Velocity (CLV)
Refers to the speed at which the information track spins in relation to the reading laser. Because tracks on the CD pass the laser head at a constant velocity, disc rotation must be faster when reading the inner radii of the disc. Typically, the CD is a CLV system.
A playback option that instructs SIREN to continually play back the current CD or playlist.
Each byte of audio data consists of an 8-bit field, called a control byte. The 8 bits in the control byte are named P, Q, R, S, T, U, V, and W, with each bit representing a subcode channel. The first two bits of the control byte contain timing information that is used to position the driver head and the remaining six bits contain user information.
A type of transition between two pieces of audio. It entails fading out of the first region while the second region is fading in.
D |
The speed from which data can be read from the CD drive.
A unit used to represent a ratio between two numbers using a logarithmic scale. For example, when comparing the numbers 14 and 7, you could say 14 is two times greater than the number 7; or you could say 14 is 6 dB greater than the number 7. Where did we pull that 6 dB from? Engineers use the equation dB = 20 x log (V1/V2) when comparing two instantaneous values. Decibels are commonly used when dealing with sound because the ear perceives loudness in a logarithmic scale.
In SIREN most measurements are given in decibels. For example, if you want to double the amplitude of a sound, you apply a 6 dB gain. A sample value of 32,767 (maximum positive sample value for 16-bit sound) can be referred to as having a value of 0 dB. Likewise, a sample value of 16,384 can be referred to having a value of -6 dB.
A program that enables Windows to connect different hardware and software. For example, a sound card device driver is used by Windows software to control sound card recording and playback.
Digital Audio Extraction (DAE)
SIREN uses DAE to read music from CDs as the first step of the recording process. The second step is encoding. SIREN uses DAE and then encoding when it records music from a CD to your computer.
DRM - Digital Rights Management
The secure exchange of intellectual property, such as copyright-protected music or text, in digital form over the Internet or other electronic media, such as CDs and removable disks. DRM allows content owners to distribute digital products quickly, safely, and securely to authorized recipients.
Digital Signal Processing (DSP)
A general term describing anything that alters digital data. Signal processors have existed for a very long time (tone controls, distortion boxes, wah-wah pedals) in the analog (electrical) domain. Digital Signal Processors alter the data after it has been digitized by using a combination of programming and mathematical techniques. DSP techniques are used to perform many effects such as equalization and reverb simulation.
Since most DSP is performed with simple arithmetic operations (additions and multiplications), both your computer's processor and specialized DSP chips can be used to perform any DSP operation. The difference is that DSP chips are optimized specifically for mathematical functions while your computer's microprocessor is not. This results in a difference in processing speed.
A complilation of interpreters that allow sound and video to work faster in Windows 95 and later and Windows NT 4 and later.
Disc-at-Once (DAO, Single Session)
Disc-at-once writing is the most common burning method in the music industry. This writing mode is used when creating a "master" disc to be sent to a disc manufacturer for mass replication. Disc-at-once works just as it sounds. Once the premastering software has created a cue sheet, the Table of Contents (TOC) is written to the lead-in area. At this point, the audio to be recorded is written to the CD in one recording session. After all of the audio has been written, a final fixation is automatically performed by writing the required silence to the lead-out area. This writing procedure is opposite of track-at-once writing, in which the TOC is written to the lead-in area after all data has been written to the disc. SIREN writes CDs using track-at-once writing.
A quick way to perform certain operations using the mouse in SIREN. To drag and drop, you click and hold a highlighted selection, drag it (hold the left-mouse button down and move the mouse) and drop it (let go of the mouse button) at another position on the screen.
The difference between the maximum and minimum signal levels. It can refer to a musical performance (high volume vs. low volume signals) or to electrical equipment (peak level before distortion vs. noise floor). For example, orchestral music has a wide dynamic range while thrash metal has a very small (always loud) range.
E |
A rudimentary noise reduction process which involves a boost in the high frequencies during the recording of the CD and a complimentary cut in the same frequencies during the playback of the CD. The result reduces high frequency noise without disrupting the natural frequency response of the source material. If the emphasis flag is set for a track, any CD player that has a de-emphasis circuit will impart the high frequency cut on the track.
SIREN uses encoding to convert music data from CDs to music files. This is the second step of the recording process. The first step is digital audio extraction (DAE). SIREN uses DAE and then encoding when it records music from a CD to your computer.
The process by which certain frequency band levels are changed. EQ has various uses. In SIREN, you can adjust the EQ levels using the Graphic EQ Panel.
Contained within each frame of the compact disc. ECC is a method of correcting data errors through the use of interleaved or redundant data. Through the use of ECC, corrected data is restored to its original state.
Accomplished prior to error correction, EDC is the method used to determine errors in the digital data stream. Through the use of parity bits, data is encoded with binary digits telling the computer whether to accept or reject the data stream.
The use of Error Correction Code, Error Detection Code, and concealment to enhance the storage and playback capabilities of the compact disc.
F |
A file format specifies the way in which data is stored on a computer.
The Frequency Spectrum of a signal refers to its range of frequencies. In audio, the frequency range is basically 20 Hz to 20,000 Hz. The frequency spectrum sometimes refers to the distribution of these frequencies. For example, bass-heavy sounds have a large frequency content in the low end (20 Hz - 200 Hz) of the spectrum.
G |
Used to describe the style of music that SIREN uses to categorize music in the My Music folder. SIREN uses the genre information stored as part of the song. If this information is not available, you can add it using the Properties window.
H |
The unit of measurement for frequency or cycles per second (CPS).
I |
Industry Standard Recording Code (ISRC)
Each track on a CD may contain an ISRC in its Q subcode data, uniquely identifying a track.
L |
The area between the pits on the compact disc surface. Series of pits and lands are "burned" into the disc and represent the original audio information. The compact disc player or drive then reads the pits and lands, which are analogous to binary data, and processes this binary data into music.
Comprises approximately the first two minutes on any compact disc and is generally unused for recording actual audio data. The main purpose of this area is to store the Table of Contents (TOC), which keeps an account of each track's location on the disc.
Contains 90 seconds of silence (blank sectors) and serves as a buffer area in case the player reads past the last track on the disc. This area essentially does nothing more than let listeners know the music is over.
See Also, Perfect Clarity Audio.
M |
A standard way for Windows programs to communicate with multimedia devices like sound cards and CD players. If a device has a MCI device driver, it can easily be controlled by most multimedia Windows software.
A Microsoft Windows program that can play digital sounds or videos using MCI devices. Media Player is useful for testing your sound card setup. For example, if you can't hear sound when using SIREN, try using Media Player. If you can't play sound using Media Player, check the sound card's manual (do not call Sonic Foundry's Technical Support until you've called the sound card manufacturer).
Motion Picture Experts Group-1, Audio Layer 3 (.mp3 file) is an audio compression format invented in 1991 by a German research firm (the Fraunhofer Institute) that squeezes songs to one-twelfth the size of an audio CD file. Developed for broadcast uses, .mp3 eventually found its way onto the Internet as an ideal way to send music files back and forth. SIREN can play and record .mp3 files.
The folder in which SIREN stores and categorizes your music library. You can access this folder through the Media Library view. The My Media folder organizes your music for easy access and playback.
P |
An area within the SIREN window. You can move and resize panels within the window and can turn them on and off.
The area on a disc that precedes audio tracks (between index 0 and index 1). As required under the Red Book standards, two seconds of pause time between tracks is the minimum requirement on all audio CDs.
The information on compact discs represented by minute indentations in the polycarbonate base. These pits, in combination with the spaces in between the pits (lands), are what are ultimately read by the CD player or CD-ROM drive and interpreted as either "zeros" or "ones". The compact disc player or drive then processes this binary data into music.
A compressed file format that preserves every single bit of audio data. Unlike lossy audio formats like MP3, WMA, or RealMedia, there is absolutely no audio degradation resulting from the compression/decompression algorithm: the before and after audio stream is identical. Even the highest quality setting MP3 files are perceptively different than the original recording and continue to degrade after every encode/decode process. With the PCA audio codec, the file can be re-edited over and over without any loss whatsover, just like using a regular WAV (PCM) file.
While generic lossless data compressors like PKZip typically compresses audio files less than 5%, the Perfect Clarity Audio codec will usually make audio files between 20% to 60% smaller than the original. For an entire 60 minute CD, this can result in savings of more than 200 Megabytes of storage. For archiving large amounts of valuable recordings, the data storage savings can be huge. Also, the files will transfer through a data network that much faster.
A custom collection of songs from your music library. You can create playlists for later playback.
The area within a track of the compact disc where all user information (audio data) is stored.
PCM is the most common representation of uncompressed audio signals. This method of coding yields the highest fidelity possible when using digital storage.
Q |
The process by which measurements are rounded to discrete values. Specifically with respect to audio, quantization is a function of the analog to digital conversion process. The continuous variation of the voltages of a analog audio signal are quantized to discrete amplitude values represented by digital, binary numbers. The number of bits available to describe these values determines the resolution or accuracy of quantization. For example, if you have 8-bit analog to digital converters, the varying analog voltage must be quantized to 1 of 256 discrete values; a 16-bit converter has 65,536 values.
A result of describing an analog signal in discrete digital terms (see quantization). This noise is most easily heard in low resolution digital sounds that have low bit depths and is similar to a "shhhhh" type sound while the audio is playing. It becomes more apparent when the signal is at low levels, such as when doing a fade out.
R |
Recorder Unique Identifier (RID)
Each track on a CD may contain an RID in its Q subcode which identifies a unique drive on which this CD was recorded. The RID helps prevent unauthorized copying of tracks by enabling the source of any recording to be identified.
Defines the specifications of the audio compact disc. Red Book specifications define not only the information within the disc (digital audio recorded at 44.1 kHz), but also the disc size itself and the way in which audio is arranged.
S |
The word sample is used in many different (and often confusing) ways when talking about digital sound. Here are some of the different meanings:
A discrete point in time which a sound signal is divided into when digitizing. For example, an audio CD-ROM contains 44,100 samples per second. Each sample is really only a number which contains the amplitude value of a waveform measured over time.
A sound which has been recorded in a digital format; used by musicians who make short recordings of musical instruments to be used for composition and performance of music or sound effects. These recordings are called samples. In this Help system, we try to use sound file instead of sample whenever referring to a digital recording.
The act of recording sound digitally, i.e. to sample an instrument means to digitize and store it.
The Sample Rate (also referred to as the Sampling Rate or Sampling Frequency) is the number of samples per second used to store a sound. High sample rates, such as 44,100 Hz provide higher fidelity than lower sample rates, such as 11,025 Hz. However, more storage space is required when using higher sample rates.
See Bit Depth.
The Sample Value (also referred to as sample amplitude) is the number stored by a single sample. In 16-bit audio, these values range from -32768 to 32767. In 8-bit audio, they range from -128 to 127. The maximum allowed sample value is often referred to as 100% or 0 dB.
SCSI Pass-Through Interface (SPTI)
An interface on windows NT platforms that allows you to talk directly to the SCSI drivers and send SCSI commands to the device.
A drive that returns Q data to the application, allowing the determination of whether a track is a second generation copy. A SCMS-R drive also allows UPC, ISRC, and RID data to be retrieved at the same time.
A drive that allows Q data to be generated on a disc to track second generation copies of audio as well as UPC, ISRC, and RID data.
Serial Copy Management System (SCMS)
Federally mandated copy protection method. This system enables you to copy music from audio CDs to your computer, and then enables you to create a CD from this music for personal use. SCMS prevents you from making a copy of this copy.
A context-sensitive menu which appears when you click on certain areas of the screen. The functions available in the shortcut menu depend on the object being clicked on as well as the state of the program. As with any menu, you can select an item from the shortcut menu to perform an operation. Shortcut menus are used frequently in SIREN for quick access to many commands. An example of a shortcut menu can be found by right-clicking on any waveform display in a data window.
The signal-to-noise ratio (SNR) is a measurement of the difference between a recorded signal and noise levels. A high SNR is always the goal.
The maximum signal-to-noise ratio of digital audio is determined by the number of bits per sample. In 16-bit audio, the signal to noise ratio is 96 dB while in 8-bit audio its 48 dB. However, in practice this SNR is never achieved, especially when using low-end electronics.
Small Computer Systems Interface (SCSI)
A standard high-speed parallel interface defined by the American National Standards Institute (ANSI) that defines standard physical and electrical connections for devices. SCSI provides a standard interface that enables many different kinds of devices, such as disk drives, magneto optical disks, CD-ROM drives, and tape drives to interface with the host computer.
The sound card is the audio interface between your computer and the outside world. It is responsible for converting analog signals to digital and vice versa. There are a million sound cards available on the market today covering the spectrum of quality and price. SIREN will work with any Windows compatible sound card.
Sonic Foundry's Sound Forge is a professional sound editing software for Windows that includes an extensive set of audio processes, tools, and effects for manipulating audio.
Mixer implementation that includes 2 discrete channels.
The 8 bits in the control byte, named P,Q,R,S,T,U,V,W, where each bit represents a subcode channel. The first two bits of the Control Byte contain timing information that is used to position the driver head and the remaining six bits contain user information. The "P" channel indicates what part of the disc is being read: Lead-In, Program, or Lead-Out. The "P" channel also indicates start times and end times for each track on the disc. Compact disc players use the "Q" channel to display the music playing time. The "Q" channel is broken down into three modes. The majority of audio CD titles do not use the "R through W" channels and about 99.9% of all CD players ignore the R-W channels altogether.
T |
Non-audio data, contained in the lead-in area, which keeps an account of each track's location on the disc. Specifically, contains a listing of initialization data and track and time information.
Tempo is the rhythmic rate of a musical composition, usually specified in Beats Per Minute (BPM).
Each track is normally equivalent to one song on a CD. The Red Book Standard allows up to 99 tracks on a CD-DA disc. Tracks contain series of pits and lands, which represent the information audio information.
Track-at-once writing records either one track or multiple tracks to the disc and results in a partially recorded disc. Because the data in the program area is written before the lead-in area (including the Table of Contents), the CD-R disc remains unplayable on most systems until you add the final track and perform a final fixation (close the CD session). The advantage of this type of writing is that you can record tracks onto the disc as you finish them, as opposed to waiting until you have finished the entire album (as you do with disc-at-once writing). SIREN uses track-at-once writing for writing CDs.
SIREN window area that provides easy access to common commands used while playing music.
U |
Each CD may contain a UPC in its Q subcode data, uniquely identifying the disc.
W |
Standard audio format used on Windows-based computers. SIREN can play back .wav files and can convert them to .wma files.
A Waveform is the visual representation of wave-like phenomena, such as sound or light. For example, when the amplitude of sound pressure is graphed over time, pressure variations usually form a smooth waveform.
Windows Media Audio File(.wma)
Microsoft compressed audio format that provides security features that prevent unauthorized duplication. In addition to playing .wma files, SIREN can also create .wma files from music that you've recorded from audio CDs and from .wav and .mp3 files.