romikgosai/squad_modified_2 huggingface dataset:
Tonearm skating forces and other perturbations are also picked up by the stylus. This is a form of frequency multiplexing as the control signal (restoring force) used to keep the stylus in the groove is carried by the same mechanism as the sound itself. Subsonic frequencies below about 20 Hz in the audio signal are dominated by tracking effects, which is one form of unwanted rumble ("tracking noise") and merges with audible frequencies in the deep bass range up to about 100 Hz. High fidelity sound equipment can reproduce tracking noise and rumble. During a quiet passage, woofer speaker cones can sometimes be seen to vibrate with the subsonic tracking of the stylus, at frequencies as low as just above 0.5 Hz (the frequency at which a 33 1⁄3 rpm record turns on the turntable; 5⁄9 Hz exactly on an ideal turntable). Another reason for very low frequency material can be a warped disk: its undulations produce frequencies of only a few hertz and present day amplifiers have large power bandwidths. For this reason, many stereo receivers contained a switchable subsonic filter. Some subsonic content is directly out of phase in each channel. If played back on a mono subwoofer system, the noise will cancel, significantly reducing the amount of rumble that is reproduced.

Q1: What would be a cause of low frequency sounds when listening?
A1: warped disk
Q2: What is a feature many stereos contain to fight back against unwanted noises?
A2: subsonic filter
Q3: What is a sounds commonly heard when listening to a vinyl that is unintentional.
A3: Tonearm skating
Q4: Which frequencies are you most likely to hear tonearm skating?
A4: frequencies below about 20 Hz
Q5: Are there any visual signs of tracking when listening to a record?
A5: cones can sometimes be seen to vibrate with the subsonic tracking
Due to recording mastering and manufacturing limitations, both high and low frequencies were removed from the first recorded signals by various formulae. With low frequencies, the stylus must swing a long way from side to side, requiring the groove to be wide, taking up more space and limiting the playing time of the record. At high frequencies, hiss, pops, and ticks are significant. These problems can be reduced by using equalization to an agreed standard. During recording the amplitude of low frequencies is reduced, thus reducing the groove width required, and the amplitude at high frequencies is increased. The playback equipment boosts bass and cuts treble so as to restore the tonal balance in the original signal; this also reduces the high frequency noise. Thus more music will fit on the record, and noise is reduced.

Q1: What is a limitation of low frequency recordings?
A1: limiting the playing time
Q2: What kinds of unwanted sounds are often heard at high frequencies?
A2: hiss, pops, and ticks
Q3: What is done during recordings to help reduce unwanted sounds?
A3: amplitude of low frequencies is reduced
Q4: What is a benefit of using equalization devices?
A4: problems can be reduced
Q5: What is done to high frequency  sounds to lessen sound issues?
A5: amplitude at high frequencies is increased
In 1926 Joseph P. Maxwell and Henry C. Harrison from Bell Telephone Laboratories disclosed that the recording pattern of the Western Electric "rubber line" magnetic disc cutter had a constant velocity characteristic. This meant that as frequency increased in the treble, recording amplitude decreased. Conversely, in the bass as frequency decreased, recording amplitude increased. Therefore, it was necessary to attenuate the bass frequencies below about 250 Hz, the bass turnover point, in the amplified microphone signal fed to the recording head. Otherwise, bass modulation became excessive and overcutting took place into the next record groove. When played back electrically with a magnetic pickup having a smooth response in the bass region, a complementary boost in amplitude at the bass turnover point was necessary. G. H. Miller in 1934 reported that when complementary boost at the turnover point was used in radio broadcasts of records, the reproduction was more realistic and many of the musical instruments stood out in their true form.

Q1: Whom found that they can make musical instruments sound more natural with an amplifier boost at the turnover point?
A1: G. H. Miller
Q2: What is found when a complementary boost is used at the bass turnover point?
A2: reproduction was more realistic
Q3: When frequency in the treble increases what happens to the recording amplitude?
A3: recording amplitude decreased
Q4: What happens when frequency decreases in the bass?
A4: recording amplitude increased
West in 1930 and later P. G. A. H. Voigt (1940) showed that the early Wente-style condenser microphones contributed to a 4 to 6 dB midrange brilliance or pre-emphasis in the recording chain. This meant that the electrical recording characteristics of Western Electric licensees such as Columbia Records and Victor Talking Machine Company in the 1925 era had a higher amplitude in the midrange region. Brilliance such as this compensated for dullness in many early magnetic pickups having drooping midrange and treble response. As a result, this practice was the empirical beginning of using pre-emphasis above 1,000 Hz in 78 rpm and 33 1⁄3 rpm records.

Q1: Whom found Wente-style condenser microphones helpful?
A1: P. G. A. H. Voigt
Q2: How were Wente-Style condenser microphones helpful?
A2: pre-emphasis in the recording
Q3: When was a pre-emphasis most useful?
A3: above 1,000 Hz
Q4: On which recording types were pre-emphasis used most in the 1920s?
A4: 78 rpm and 33 1⁄3 rpm
Q5: In which Era was this finding most significant?
A5: 1925 era
Over the years a variety of record equalization practices emerged and there was no industry standard. For example, in Europe recordings for years required playback with a bass turnover setting of 250–300 Hz and a treble roll-off at 10,000 Hz ranging from 0 to −5 dB or more. In the US there were more varied practices and a tendency to use higher bass turnover frequencies such as 500 Hz as well as a greater treble rolloff like −8.5 dB and even more to record generally higher modulation levels on the record.

Q1: What was the industry standard in Europe for record equalization?
A1: there was no industry standard
Q2: In which country was the treble roll off greater?
A2: US
Q3: Which country prefers a bass turnover setting of 250-300 Hz?
A3: Europe
Q4: What was the industry standard on equalization practices?
A4: there was no industry standard
Q5: Which country used the most varied equalization practices?
A5: US
Evidence from the early technical literature concerning electrical recording suggests that it wasn't until the 1942–1949 period that there were serious efforts to standardize recording characteristics within an industry. Heretofore, electrical recording technology from company to company was considered a proprietary art all the way back to the 1925 Western Electric licensed method used by Columbia and Victor. For example, what Brunswick-Balke-Collender (Brunswick Corporation) did was different from the practices of Victor.

Q1: How far back did records show the art of sound recordings?
A1: 1925
Q2: How was standardization prior to 1942?
A2: considered a proprietary art
Q3: Around what time period was there an attempt made to standardize recordings?
A3: 1942–1949
Broadcasters were faced with having to adapt daily to the varied recording characteristics of many sources: various makers of "home recordings" readily available to the public, European recordings, lateral-cut transcriptions, and vertical-cut transcriptions. Efforts were started in 1942 to standardize within the National Association of Broadcasters (NAB), later known as the National Association of Radio and Television Broadcasters (NARTB). The NAB, among other items, issued recording standards in 1949 for laterally and vertically cut records, principally transcriptions. A number of 78 rpm record producers as well as early LP makers also cut their records to the NAB/NARTB lateral standard.

Q1: Who made the move to standardize recordings?
A1: National Association of Broadcasters
Q2: When were recording standards officially released?
A2: 1949
Q3:  Which recording types were effected by the imposed industry standards?
A3: laterally and vertically cut records, principally transcriptions.
Q4: What was one issue of a lack of industry standards?
A4: Broadcasters were faced with having to adapt daily to the varied recording
Q5: What is the NAB?
A5: National Association of Broadcasters
The lateral cut NAB curve was remarkably similar to the NBC Orthacoustic curve that evolved from practices within the National Broadcasting Company since the mid-1930s. Empirically, and not by any formula, it was learned that the bass end of the audio spectrum below 100 Hz could be boosted somewhat to override system hum and turntable rumble noises. Likewise at the treble end beginning at 1,000 Hz, if audio frequencies were boosted by 16 dB at 10,000 Hz the delicate sibilant sounds of speech and high overtones of musical instruments could survive the noise level of cellulose acetate, lacquer/aluminum, and vinyl disc media. When the record was played back using a complementary inverse curve, signal-to-noise ratio was improved and the programming sounded more lifelike.

Q1: What bass settings were needed to eliminate hum?
A1: below 100 Hz
Q2: What helped cause the most life like sound?
A2: using a complementary inverse curve
Q3: How did the NBC Othacoustic curve relate to the NAB curve?
A3: remarkably similar
Q4: What was a benefit to broadcasters of recording standards?
A4: programming sounded more lifelike.
Ultimately, the New Orthophonic curve was disclosed in a publication by R.C. Moyer of RCA Victor in 1953. He traced RCA Victor characteristics back to the Western Electric "rubber line" recorder in 1925 up to the early 1950s laying claim to long-held recording practices and reasons for major changes in the intervening years. The RCA Victor New Orthophonic curve was within the tolerances for the NAB/NARTB, Columbia LP, and AES curves. It eventually became the technical predecessor to the RIAA curve.

Q1: How far back could these recording practices be traced?
A1: 1925
Q2: What were the recording standards based off from?
A2: long-held recording practices
Q3: What became the predecessor to the RIAA curve?
A3: New Orthophonic curve
Q4: Who developed the New Orthophonic curve?
A4: RCA Victor
Q5: Whom wrote the publication outlining the New Orthophonic curve?
A5: R.C. Moyer
Delicate sounds and fine overtones were mostly lost, because it took a lot of sound energy to vibrate the recording horn diaphragm and cutting mechanism. There were acoustic limitations due to mechanical resonances in both the recording and playback system. Some pictures of acoustic recording sessions show horns wrapped with tape to help mute these resonances. Even an acoustic recording played back electrically on modern equipment sounds like it was recorded through a horn, notwithstanding a reduction in distortion because of the modern playback. Toward the end of the acoustic era, there were many fine examples of recordings made with horns.

Q1: What was the quality of sound recordings made with horns at the end of the acoustic era?
A1: many fine examples
Q2: What were issues facing play back and recording mechanics?
A2: acoustic limitations
Q3: Why do photos show take on horns?
A3: help mute these resonances
Q4: What was the cause of delicate and fine sound loss?
A4: took a lot of sound energy
Q5: How would a record recorded with a horn sound played through modern equipment?
A5: like it was recorded through a horn
Electric recording which developed during the time that early radio was becoming popular (1925) benefited from the microphones and amplifiers used in radio studios. The early electric recordings were reminiscent tonally of acoustic recordings, except there was more recorded bass and treble as well as delicate sounds and overtones cut on the records. This was in spite of some carbon microphones used, which had resonances that colored the recorded tone. The double button carbon microphone with stretched diaphragm was a marked improvement. Alternatively, the Wente style condenser microphone used with the Western Electric licensed recording method had a brilliant midrange and was prone to overloading from sibilants in speech, but generally it gave more accurate reproduction than carbon microphones.

Q1: What technique offered realistic sounds during playback?
A1: Western Electric licensed recording method
Q2: At at time was radio gaining popularity?
A2: 1925
Q3: What type of microphones were losing popularity in the 1920s?
A3: carbon microphones used,
Q4: What benefit did the use of the Wente style condenser microphone offer?
A4: brilliant midrange
Q5: What was a benefit of early radio recordings?
A5: microphones and amplifiers
It was not unusual for electric recordings to be played back on acoustic phonographs. The Victor Orthophonic phonograph was a prime example where such playback was expected. In the Orthophonic, which benefited from telephone research, the mechanical pickup head was redesigned with lower resonance than the traditional mica type. Also, a folded horn with an exponential taper was constructed inside the cabinet to provide better impedance matching to the air. As a result, playback of an Orthophonic record sounded like it was coming from a radio.

Q1: What is one example of an acoustic phonograph on which one would listen to electric recordings?
A1: Victor Orthophonic phonograph
Q2: What allowed better sounds inside the cabinet of the orthoponic phonograph?
A2: folded horn with an exponential taper
Q3: What adjustments were made to the orthophonic  to accommodate electric recordings?
A3: mechanical pickup head was redesigned with lower resonance than the traditional mica type
Q4: Was it common to hear electric recordings on phonographs?
A4: not unusual
Q5: How similar was the sound of a orthodontic  record to a radio?
A5: sounded like
Eventually, when it was more common for electric recordings to be played back electrically in the 1930s and 1940s, the overall tone was much like listening to a radio of the era. Magnetic pickups became more common and were better designed as time went on, making it possible to improve the damping of spurious resonances. Crystal pickups were also introduced as lower cost alternatives. The dynamic or moving coil microphone was introduced around 1930 and the velocity or ribbon microphone in 1932. Both of these high quality microphones became widespread in motion picture, radio, recording, and public address applications.

Q1: What are two examples of high quality microphones?
A1: moving coil microphone was introduced around 1930 and the velocity or ribbon microphone
Q2: What was used to dampen resonances in recordings?
A2: Magnetic pickups
Q3: When would you have first found the moving coil microphone?
A3: around 1930
Q4: What was a more economical option to magnetic pickups?
A4: Crystal pickups
Q5: In what years would you find electronic recordings played electronically?
A5: 1930s and 1940s
Over time, fidelity, dynamic and noise levels improved to the point that it was harder to tell the difference between a live performance in the studio and the recorded version. This was especially true after the invention of the variable reluctance magnetic pickup cartridge by General Electric in the 1940s when high quality cuts were played on well-designed audio systems. The Capehart radio/phonographs of the era with large diameter electrodynamic loudspeakers, though not ideal, demonstrated this quite well with "home recordings" readily available in the music stores for the public to buy.

Q1: What was a benefit of the use of magnetic pickup cartridge?
A1: high quality cuts
Q2: In what era could you find good quality recordings and playbacks at home?
A2: 1940s
Q3: What was a unique feature of the Capeart radio phonographs?
A3: large diameter electrodynamic loudspeakers
Q4: How similar were live and recorded versions?
A4: harder to tell the difference
There were important quality advances in recordings specifically made for radio broadcast. In the early 1930s Bell Telephone Laboratories and Western Electric announced the total reinvention of disc recording: the Western Electric Wide Range System, "The New Voice of Action". The intent of the new Western Electric system was to improve the overall quality of disc recording and playback. The recording speed was 33 1⁄3 rpm, originally used in the Western Electric/ERPI movie audio disc system implemented in the early Warner Brothers' Vitaphone "talkies" of 1927.

Q1: When was the Western Electric System introduced?
A1: early 1930s
Q2: What two companies worked together to develop the Western Electric System?
A2: Bell Telephone Laboratories and Western Electric
Q3: What system was used by Warner Brothers?
A3: Western Electric system
Q4: What speed was used in the Western Electric System?
A4: 33 1⁄3 rpm
Q5: What was the Western Electric System believed to do?
A5: improve the overall quality
The newly invented Western Electric moving coil or dynamic microphone was part of the Wide Range System. It had a flatter audio response than the old style Wente condenser type and didn't require electronics installed in the microphone housing. Signals fed to the cutting head were pre-emphasized in the treble region to help override noise in playback. Groove cuts in the vertical plane were employed rather than the usual lateral cuts. The chief advantage claimed was more grooves per inch that could be crowded together, resulting in longer playback time. Additionally, the problem of inner groove distortion, which plagued lateral cuts, could be avoided with the vertical cut system. Wax masters were made by flowing heated wax over a hot metal disc thus avoiding the microscopic irregularities of cast blocks of wax and the necessity of planing and polishing.

Q1: What was a benefit of vertical groove cuts?
A1: longer playback time
Q2: What could be avoided by using vertical groove cuts?
A2: inner groove distortion
Q3: How was the moving coil microphone unique to the Wente type?
A3: didn't require electronics installed in the microphone housing
Q4: How was sound improved using the moving coil microphone?
A4: override noise in playback
Q5: How was wax used to improve recordings?
A5: avoiding the microscopic irregularities
Vinyl pressings were made with stampers from master cuts that were electroplated in vacuo by means of gold sputtering. Audio response was claimed out to 8,000 Hz, later 13,000 Hz, using light weight pickups employing jeweled styli. Amplifiers and cutters both using negative feedback were employed thereby improving the range of frequencies cut and lowering distortion levels. Radio transcription producers such as World Broadcasting System and Associated Music Publishers (AMP) were the dominant licensees of the Western Electric wide range system and towards the end of the 1930s were responsible for two-thirds of the total radio transcription business. These recordings use a bass turnover of 300 Hz and a 10,000 Hz rolloff of −8.5 dB.

Q1: What were used to make vinyl pressings?
A1: master cuts
Q2: What were the top licensees of the Western Electric system in the 1930s?
A2: World Broadcasting System and Associated Music Publishers
Q3: Who was responsible for 2/3 of all recordings in the 1930s?
A3: World Broadcasting System and Associated Music Publishers
Q4: How was gold spluttering used in vinyl creation?
A4: cuts that were electroplated in vacuo by means of gold sputtering
The complete technical disclosure of the Columbia LP by Peter C. Goldmark, Rene' Snepvangers and William S. Bachman in 1949 made it possible for a great variety of record companies to get into the business of making long playing records. The business grew quickly and interest spread in high fidelity sound and the do-it-yourself market for pickups, turntables, amplifier kits, loudspeaker enclosure plans, and AM/FM radio tuners. The LP record for longer works, 45 rpm for pop music, and FM radio became high fidelity program sources in demand. Radio listeners heard recordings broadcast and this in turn generated more record sales. The industry flourished.

Q1: When was the business booming for do it yourself sound fanatics?
A1: 1949
Q2: What kind of recordings worked best for pop music?
A2: 45 rpm
Q3: What was used for longer recordings?
A3: LP record
Q4: What opened doors for long recordings?
A4: The complete technical disclosure of the Columbia LP by Peter C. Goldmark, Rene' Snepvangers and William S. Bachman
Q5: What aided in records sales in the 1950s?
A5: Radio listeners heard recordings broadcast
There is a theory that vinyl records can audibly represent higher frequencies than compact discs. According to Red Book specifications, the compact disc has a frequency response of 20 Hz up to 22,050 Hz, and most CD players measure flat within a fraction of a decibel from at least 20 Hz to 20 kHz at full output. Turntable rumble obscures the low-end limit of vinyl but the upper end can be, with some cartridges, reasonably flat within a few decibels to 30 kHz, with gentle roll-off. Carrier signals of Quad LPs popular in the 1970s were at 30 kHz to be out of the range of human hearing. The average human auditory system is sensitive to frequencies from 20 Hz to a maximum of around 20,000 Hz. The upper and lower frequency limits of human hearing vary per person.

Q1: What is generally the lowest sound a human can hear?
A1: 20 Hz
Q2: What is believed to better offer sounds of higher frequencies, compact discs or records?
A2: vinyl records
Q3: What is the higher end of typical human hearing?
A3: 20,000 Hz
Q4: Does the hearing range of the human vary?
A4: The upper and lower frequency limits of human hearing vary per person
For the first several decades of disc record manufacturing, sound was recorded directly on to the "master disc" at the recording studio. From about 1950 on (earlier for some large record companies, later for some small ones) it became usual to have the performance first recorded on audio tape, which could then be processed and/or edited, and then dubbed on to the master disc. A record cutter would engrave the grooves into the master disc. Early versions of these master discs were soft wax, and later a harder lacquer was used. The mastering process was originally something of an art as the operator had to manually allow for the changes in sound which affected how wide the space for the groove needed to be on each rotation.

Q1: Who would engrave the master disc of a vinyl record?
A1: record cutter
Q2: What was used in first recordings of vinyl records?
A2: soft wax
Q3: What was used in final recordings of vinyl records?
A3: harder lacquer
Q4: After the 1950s  what was a typical recording process?
A4: first recorded on audio tape, which could then be processed and/or edited, and then dubbed on to the master disc
Q5: Where were sound recordings originally made to?
A5: master disc
As the playing of gramophone records causes gradual degradation of the recording, they are best preserved by transferring them onto other media and playing the records as rarely as possible. They need to be stored on edge, and do best under environmental conditions that most humans would find comfortable. The medium needs to be kept clean, but alcohol should only be used on PVC or optical media, not on 78s.[citation needed] The equipment for playback of certain formats (e.g., 16 and 78 rpm) is manufactured only in small quantities, leading to increased difficulty in finding equipment to play the recordings.

Q1: Should alcohol be used to clean gramophone recordings?
A1: alcohol should only be used on PVC or optical media
Q2: Is gramophone equipment readily available?
A2: manufactured only in small quantities
Q3: What is the recommendation of gramophone recordings to preserve integrity?
A3: transferring them onto other media
Q4: What is a drawback of gramophone use?
A4: gradual degradation
Q5: How are gramophones best stored?
A5: on edge