rajpurkar/squad huggingface dataset:
Title: MP3

The compression works by reducing the accuracy of certain parts of a sound that are considered to be beyond the auditory resolution ability of most people. This method is commonly referred to as perceptual coding. It uses psychoacoustic models to discard or reduce precision of components less audible to human hearing, and then records the remaining information in an efficient manner.

Question: What does the compression target in the song?
Answer: accuracy

Question: The targetting focuses on what aspect that is beyond the ability of most people?
Answer: auditory resolution

Question: What is this method commonly referred to as?
Answer: perceptual coding

Question: What kind of model is used in this kind of compression?
Answer: psychoacoustic

Question: These models ensure that the precision is reduced for the components that are what to human hearing?
Answer: less audible
Title: MP3

MP3 was designed by the Moving Picture Experts Group (MPEG) as part of its MPEG-1 standard and later extended in the MPEG-2 standard. The first subgroup for audio was formed by several teams of engineers at Fraunhofer IIS, University of Hannover, AT&T-Bell Labs, Thomson-Brandt, CCETT, and others. MPEG-1 Audio (MPEG-1 Part 3), which included MPEG-1 Audio Layer I, II and III was approved as a committee draft of ISO/IEC standard in 1991, finalised in 1992 and published in 1993 (ISO/IEC 11172-3:1993). Backwards compatible MPEG-2 Audio (MPEG-2 Part 3) with additional bit rates and sample rates was published in 1995 (ISO/IEC 13818-3:1995).

Question: Who designed MP3?
Answer: Moving Picture Experts Group

Question: What was the first standard that this group had?
Answer: MPEG-1

Question: The first standard later developed into which standard?
Answer: MPEG-2

Question: When was the draft passed to have MPEG-1 Audio approved as a standard?
Answer: 1991

Question: When was MPEG-2 Audio finally published?
Answer: 1995
Title: MP3

The MP3 lossy audio data compression algorithm takes advantage of a perceptual limitation of human hearing called auditory masking. In 1894, the American physicist Alfred M. Mayer reported that a tone could be rendered inaudible by another tone of lower frequency. In 1959, Richard Ehmer described a complete set of auditory curves regarding this phenomenon. Ernst Terhardt et al. created an algorithm describing auditory masking with high accuracy. This work added to a variety of reports from authors dating back to Fletcher, and to the work that initially determined critical ratios and critical bandwidths.

Question: What does the MP3 compression take advantage of?
Answer: perceptual limitation

Question: What is the limitation in human hearing referred to as?
Answer: auditory masking

Question: Who was the physicist to report that a tone could be rendered inaudible.
Answer: Alfred M. Mayer

Question: When were audio curves described by Richard Ehmer?
Answer: 1959

Question: The initial work was aimed at determining critical ratios and what else?
Answer: critical bandwidths
Title: MP3

The psychoacoustic masking codec was first proposed in 1979, apparently independently, by Manfred R. Schroeder, et al. from Bell Telephone Laboratories, Inc. in Murray Hill, NJ, and M. A. Krasner both in the United States. Krasner was the first to publish and to produce hardware for speech (not usable as music bit compression), but the publication of his results as a relatively obscure Lincoln Laboratory Technical Report did not immediately influence the mainstream of psychoacoustic codec development. Manfred Schroeder was already a well-known and revered figure in the worldwide community of acoustical and electrical engineers, but his paper was not much noticed, since it described negative results due to the particular nature of speech and the linear predictive coding (LPC) gain present in speech. Both Krasner and Schroeder built upon the work performed by Eberhard F. Zwicker in the areas of tuning and masking of critical bands, that in turn built on the fundamental research in the area from Bell Labs of Harvey Fletcher and his collaborators. A wide variety of (mostly perceptual) audio compression algorithms were reported in IEEE's refereed Journal on Selected Areas in Communications. That journal reported in February 1988 on a wide range of established, working audio bit compression technologies, some of them using auditory masking as part of their fundamental design, and several showing real-time hardware implementations.

Question: What was first proposed in 1979?
Answer: The psychoacoustic masking codec

Question: Which country were the researchers located in?
Answer: United States

Question: Who was the first to produce hardware for speech?
Answer: Krasner

Question: What does LPC stand for?
Answer: linear predictive coding

Question: What was reported in IEEE's Journal on Selected Areas in Communications?
Answer: audio compression algorithms
Title: MP3

The immediate predecessors of MP3 were "Optimum Coding in the Frequency Domain" (OCF), and Perceptual Transform Coding (PXFM). These two codecs, along with block-switching contributions from Thomson-Brandt, were merged into a codec called ASPEC, which was submitted to MPEG, and which won the quality competition, but that was mistakenly rejected as too complex to implement. The first practical implementation of an audio perceptual coder (OCF) in hardware (Krasner's hardware was too cumbersome and slow for practical use), was an implementation of a psychoacoustic transform coder based on Motorola 56000 DSP chips.

Question: What does OCF stand for?
Answer: Optimum Coding in the Frequency Domain

Question: What does PXFM stand for?
Answer: Perceptual Transform Coding

Question: What was the name of the codec that OCF, PFXM and other contributes merged into?
Answer: ASPEC

Question: Which competition did ASPEC win?
Answer: quality

Question: What was the first practical implementation based on?
Answer: Motorola 56000 DSP chips
Title: MP3

As a doctoral student at Germany's University of Erlangen-Nuremberg, Karlheinz Brandenburg began working on digital music compression in the early 1980s, focusing on how people perceive music. He completed his doctoral work in 1989. MP3 is directly descended from OCF and PXFM, representing the outcome of the collaboration of Brandenburg—working as a postdoc at AT&T-Bell Labs with James D. Johnston ("JJ") of AT&T-Bell Labs—with the Fraunhofer Institut for Integrated Circuits, Erlangen, with relatively minor contributions from the MP2 branch of psychoacoustic sub-band coders. In 1990, Brandenburg became an assistant professor at Erlangen-Nuremberg. While there, he continued to work on music compression with scientists at the Fraunhofer Society (in 1993 he joined the staff of the Fraunhofer Institute).

Question: What kind of student was Karlheinz Brandenburg?
Answer: doctoral

Question: When did Karlheinz start working on digitmal music compression?
Answer: early 1980s

Question: Where did Bradenburg become an assistant professor at?
Answer: Erlangen-Nuremberg

Question: Who did Brandenburg work with in music compression?
Answer: Fraunhofer Society

Question: When did Brandenburg join the Fraunhofen Institute?
Answer: 1993
Title: MP3

The song "Tom's Diner" by Suzanne Vega was the first song used by Karlheinz Brandenburg to develop the MP3. Brandenburg adopted the song for testing purposes, listening to it again and again each time refining the scheme, making sure it did not adversely affect the subtlety of Vega's voice.

Question: What was the name of the first song used to develop the MP3?
Answer: Tom's Diner

Question: Who was the artist of the first song used?
Answer: Suzanne Vega

Question: Who adjusted the song?
Answer: Karlheinz Brandenburg

Question: The song was listened to multiple times to try and refine what?
Answer: scheme

Question: What particular aspect of the artists voice was he trying to preserve?
Answer: subtlety
Title: MP3

In 1991, there were only two proposals available that could be completely assessed for an MPEG audio standard: Musicam (Masking pattern adapted Universal Subband Integrated Coding And Multiplexing) and ASPEC (Adaptive Spectral Perceptual Entropy Coding). The Musicam technique, as proposed by Philips (the Netherlands), CCETT (France) and Institut für Rundfunktechnik (Germany) was chosen due to its simplicity and error robustness, as well as its low computational power associated with the encoding of high quality compressed audio. The Musicam format, based on sub-band coding, was the basis of the MPEG Audio compression format (sampling rates, structure of frames, headers, number of samples per frame).

Question: How many proposals were available in 1991?
Answer: two

Question: Other than ASPEC what was another proposal?
Answer: Musicam

Question: The Musicam format was proposed by Philips, based in which country?
Answer: Netherlands

Question: Which other quality alongside simplicty was key in selecting this proposal?
Answer: error robustness

Question: What was the Musican format based on?
Answer: sub-band coding
Title: MP3

Much of its technology and ideas were incorporated into the definition of ISO MPEG Audio Layer I and Layer II and the filter bank alone into Layer III (MP3) format as part of the computationally inefficient hybrid filter bank. Under the chairmanship of Professor Musmann (University of Hannover) the editing of the standard was made under the responsibilities of Leon van de Kerkhof (Layer I) and Gerhard Stoll (Layer II).

Question: What was only incorporated into Layer III and not Layers I or II?
Answer: filter bank

Question: Who was the chair that oversaw the editing of the standard?
Answer: Professor Musmann

Question: Who's responsibility was it to edit the standard for Layer I?
Answer: Leon van de Kerkhof

Question: Who's responsibility was it to edit the standard for Layer II?
Answer: Gerhard Stoll
Title: MP3

ASPEC was the joint proposal of AT&T Bell Laboratories, Thomson Consumer Electronics, Fraunhofer Society and CNET. It provided the highest coding efficiency.

Question: What was the name given to the proposal?
Answer: ASPEC

Question: What did the joint proposal provide?
Answer: the highest coding efficiency

Question: Other than Thomson Consumer Electronics, Fraunhofer Society and CNET, who else was a part of the joint proposal?
Answer: AT&T Bell Laboratories
Title: MP3

A working group consisting of Leon van de Kerkhof (The Netherlands), Gerhard Stoll (Germany), Leonardo Chiariglione (Italy), Yves-François Dehery (France), Karlheinz Brandenburg (Germany) and James D. Johnston (USA) took ideas from ASPEC, integrated the filter bank from Layer 2, added some of their own ideas and created MP3, which was designed to achieve the same quality at 128 kbit/s as MP2 at 192 kbit/s.

Question: What did the working group integrate their ideas with?
Answer: filter bank

Question: Where was the filter bank taken from?
Answer: Layer 2

Question: What did the working group take ideas from?
Answer: ASPEC

Question: What did the working group eventually create?
Answer: MP3

Question: What quality were they hoping to match at 128 kbit/s?
Answer: MP2 at 192 kbit/s
Title: MP3

All algorithms for MPEG-1 Audio Layer I, II and III were approved in 1991 and finalized in 1992 as part of MPEG-1, the first standard suite by MPEG, which resulted in the international standard ISO/IEC 11172-3 (a.k.a. MPEG-1 Audio or MPEG-1 Part 3), published in 1993.

Question: When were the algorithms approved?
Answer: 1991

Question: When were the approved algorithms finalized?
Answer: 1992

Question: What was the first started suite by MPEG?
Answer: MPEG-1

Question: What was the official name of the internation standard?
Answer: ISO/IEC 11172-3

Question: When was the international standard published?
Answer: 1993
Title: MP3

Further work on MPEG audio was finalized in 1994 as part of the second suite of MPEG standards, MPEG-2, more formally known as international standard ISO/IEC 13818-3 (a.k.a. MPEG-2 Part 3 or backwards compatible MPEG-2 Audio or MPEG-2 Audio BC), originally published in 1995. MPEG-2 Part 3 (ISO/IEC 13818-3) defined additional bit rates and sample rates for MPEG-1 Audio Layer I, II and III. The new sampling rates are exactly half that of those originally defined in MPEG-1 Audio. This reduction in sampling rate serves to cut the available frequency fidelity in half while likewise cutting the bitrate by 50%. MPEG-2 Part 3 also enhanced MPEG-1's audio by allowing the coding of audio programs with more than two channels, up to 5.1 multichannel.

Question: Further work on MPEG was finalized as a part of which MPEG standard?
Answer: second suite

Question: What was the official name of ISO/IEC 13818-3 better known as?
Answer: MPEG-2

Question: At what rate were the new sampling rates defined in comparison to MPEG-1 Audio?
Answer: half

Question: Apart from cutting the frequency fidelity in half, what else was cut in half?
Answer: bitrate

Question: Allowing the coding of audio programs with more than two channels was a major aspect of what?
Answer: MPEG-2 Part 3
Title: MP3

An additional extension to MPEG-2 is named MPEG-2.5 audio, as MPEG-3 already had a different meaning. This extension was developed at Fraunhofer IIS, the registered MP3 patent holders. Like MPEG-2, MPEG-2.5 adds new sampling rates exactly half of that previously possible with MPEG-2. It thus widens the scope of MP3 to include human speech and other applications requiring only 25% of the frequency reproduction possible with MPEG-1. While not an ISO recognized standard, MPEG-2.5 is widely supported by both inexpensive and brand name digital audio players as well as computer software based MP3 encoders and decoders. A sample rate comparison between MPEG-1, 2 and 2.5 is given further down. MPEG-2.5 was not developed by MPEG and was never approved as an international standard. MPEG-2.5 is thus an unofficial or proprietary extension to the MP3 format.

Question: As MPEG-3 had a different meaning, what was the name given to the extension of MPEG-2?
Answer: MPEG-2.5 audio

Question: Where was this extension developed?
Answer: Fraunhofer IIS

Question: The new sampling rates widened the scope of MP3 to be able to include what?
Answer: human speech

Question: What is not an ISO recognized standard?
Answer: MPEG-2.5

Question: As MPEG-2.5 is unofficial, it is considered what kind of extension to the MP3 format?
Answer: proprietary
Title: MP3

Compression efficiency of encoders is typically defined by the bit rate, because compression ratio depends on the bit depth and sampling rate of the input signal. Nevertheless, compression ratios are often published. They may use the Compact Disc (CD) parameters as references (44.1 kHz, 2 channels at 16 bits per channel or 2×16 bit), or sometimes the Digital Audio Tape (DAT) SP parameters (48 kHz, 2×16 bit). Compression ratios with this latter reference are higher, which demonstrates the problem with use of the term compression ratio for lossy encoders.

Question: What defines the compression efficiency of encoders?
Answer: bit rate

Question: Compression ratio depends on the sample rate and bit depth of which signal?
Answer: input

Question: What does CD stand for?
Answer: Compact Disc

Question: Other than CD parameters, what else can be used as parameter references?
Answer: Digital Audio Tape (DAT) SP

Question: What can CD parameters be used as references for?
Answer: compression ratios
Title: MP3

Karlheinz Brandenburg used a CD recording of Suzanne Vega's song "Tom's Diner" to assess and refine the MP3 compression algorithm. This song was chosen because of its nearly monophonic nature and wide spectral content, making it easier to hear imperfections in the compression format during playbacks. Some refer to Suzanne Vega as "The mother of MP3". This particular track has an interesting property in that the two channels are almost, but not completely, the same, leading to a case where Binaural Masking Level Depression causes spatial unmasking of noise artifacts unless the encoder properly recognizes the situation and applies corrections similar to those detailed in the MPEG-2 AAC psychoacoustic model. Some more critical audio excerpts (glockenspiel, triangle, accordion, etc.) were taken from the EBU V3/SQAM reference compact disc and have been used by professional sound engineers to assess the subjective quality of the MPEG Audio formats.

Question: What type of recording did Brandenburg use?
Answer: CD

Question: What did Brandenburg use the recording to refine?
Answer: the MP3 compression algorithm

Question: What word describes the nature of the song used?
Answer: monophonic

Question: As a result of her song being used, Suzanne Vega is sometimes referred to as what?
Answer: The mother of MP3

Question: Excerpts were taken from which reference compact disc to assess the subjective quality of the MPEG audio formats?
Answer: EBU V3/SQAM
Title: MP3

A reference simulation software implementation, written in the C language and later known as ISO 11172-5, was developed (in 1991–1996) by the members of the ISO MPEG Audio committee in order to produce bit compliant MPEG Audio files (Layer 1, Layer 2, Layer 3). It was approved as a committee draft of ISO/IEC technical report in March 1994 and printed as document CD 11172-5 in April 1994. It was approved as a draft technical report (DTR/DIS) in November 1994, finalized in 1996 and published as international standard ISO/IEC TR 11172-5:1998 in 1998. The reference software in C language was later published as a freely available ISO standard. Working in non-real time on a number of operating systems, it was able to demonstrate the first real time hardware decoding (DSP based) of compressed audio. Some other real time implementation of MPEG Audio encoders were available for the purpose of digital broadcasting (radio DAB, television DVB) towards consumer receivers and set top boxes.

Question: Who developed the reference simulation software?
Answer: the ISO MPEG Audio committee

Question: Which language was the reference simulation software written in?
Answer: C

Question: When was the reference software approved?
Answer: March 1994

Question: When did the reference software become an international standard?
Answer: 1998

Question: What could the reference software demonstrate?
Answer: real time hardware decoding
Title: MP3

On 7 July 1994, the Fraunhofer Society released the first software MP3 encoder called l3enc. The filename extension .mp3 was chosen by the Fraunhofer team on 14 July 1995 (previously, the files had been named .bit). With the first real-time software MP3 player WinPlay3 (released 9 September 1995) many people were able to encode and play back MP3 files on their PCs. Because of the relatively small hard drives back in that time (~ 500–1000 MB) lossy compression was essential to store non-instrument based (see tracker and MIDI) music for playback on computer.

Question: When was the first software MP3 encoder released?
Answer: 7 July 1994

Question: What was the name of the first software MP3 encoder?
Answer: l3enc

Question: What was the filename extension?
Answer: .mp3

Question: What was the name of the first real-time software MP3 player?
Answer: WinPlay3

Question: What was the average high end hard drive size?
Answer: 1000 MB
Title: MP3

As sound scholar Jonathan Sterne notes, "An Australian hacker acquired l3enc using a stolen credit card. The hacker then reverse-engineered the software, wrote a new user interface, and redistributed it for free, naming it "thank you Fraunhofer"".

Question: What was Jonathan Sterne's profession?
Answer: sound scholar

Question: Which nationality was the hacker who acquired I3enc?
Answer: Australian

Question: What did the hacker use to acquire the software?
Answer: stolen credit card

Question: The hacker re-wrote which element of the program?
Answer: user interface

Question: How much did the new released program by the hacker cost?
Answer: free
Title: MP3

In the second half of '90s, MP3 files began to spread on the Internet. The popularity of MP3s began to rise rapidly with the advent of Nullsoft's audio player Winamp, released in 1997. In 1998, the first portable solid state digital audio player MPMan, developed by SaeHan Information Systems which is headquartered in Seoul, South Korea, was released and the Rio PMP300 was sold afterwards in 1998, despite legal suppression efforts by the RIAA.

Question: Where did MP3s begin to spread?
Answer: the Internet

Question: Which audio player was released in 1997?
Answer: Winamp

Question: Who released the audio player?
Answer: Nullsoft

Question: What was the name of the first portable solid state digital audio player?
Answer: MPMan

Question: In which country was the first portable audio player developed?
Answer: South Korea
Title: MP3

In November 1997, the website mp3.com was offering thousands of MP3s created by independent artists for free. The small size of MP3 files enabled widespread peer-to-peer file sharing of music ripped from CDs, which would have previously been nearly impossible. The first large peer-to-peer filesharing network, Napster, was launched in 1999.

Question: Which website offered MP3s for free?
Answer: mp3.com

Question: How many MP3s were offered for free by the website?
Answer: thousands

Question: What kind of file sharing became popular due to the file sizes of MP3s?
Answer: peer-to-peer

Question: How did people come into possession of MP3s?
Answer: ripped from CDs

Question: Which network was the first large peer to peer file sharing network?
Answer: Napster
Title: MP3

The ease of creating and sharing MP3s resulted in widespread copyright infringement. Major record companies argued that this free sharing of music reduced sales, and called it "music piracy". They reacted by pursuing lawsuits against Napster (which was eventually shut down and later sold) and against individual users who engaged in file sharing.

Question: What kind of infringement resulted from sharing MP3s?
Answer: copyright

Question: What name did the record companies associate with MP3 file sharing?
Answer: music piracy

Question: Who was the target of the record companies?
Answer: Napster

Question: What happened to Napster?
Answer: shut down and later sold
Title: MP3

Unauthorized MP3 file sharing continues on next-generation peer-to-peer networks. Some authorized services, such as Beatport, Bleep, Juno Records, eMusic, Zune Marketplace, Walmart.com, Rhapsody, the recording industry approved re-incarnation of Napster, and Amazon.com sell unrestricted music in the MP3 format.

Question: What kind of MP3 file sharing continues on?
Answer: Unauthorized

Question: Beatport, Bleep and Juno records are examples of what kind of service?
Answer: authorized

Question: What kind of music is sold by these companies?
Answer: unrestricted

Question: Which format is used by the companies that sell the music legally?
Answer: MP3
Title: MP3

An MP3 file is made up of MP3 frames, which consist of a header and a data block. This sequence of frames is called an elementary stream. Due to the "byte reservoir", frames are not independent items and cannot usually be extracted on arbitrary frame boundaries. The MP3 Data blocks contain the (compressed) audio information in terms of frequencies and amplitudes. The diagram shows that the MP3 Header consists of a sync word, which is used to identify the beginning of a valid frame. This is followed by a bit indicating that this is the MPEG standard and two bits that indicate that layer 3 is used; hence MPEG-1 Audio Layer 3 or MP3. After this, the values will differ, depending on the MP3 file. ISO/IEC 11172-3 defines the range of values for each section of the header along with the specification of the header. Most MP3 files today contain ID3 metadata, which precedes or follows the MP3 frames, as noted in the diagram.

Question: A header and data block together make up what?
Answer: MP3 frames

Question: What is a sequence of MP3 frames called?
Answer: elementary stream

Question: What is used to identify the begining of a valid frame of an MP3 header?
Answer: dard

Question: How many bits are needed to indicate that layer 3 is used?
Answer: two

Question: MP3 files today contain what kind of metadeta?
Answer: ID3