International Journal of Digital Multimedia Broadcasting / 2019 / Article / Tab 9

Research Article

Subjective Evaluation of Music Compressed with the ACER Codec Compared to AAC, MP3, and Uncompressed PCM

Table 9

Summary of thematic analysis results.

ThemeDefinitionnExample Response

1. DistortionManipulation or processing of the original signal, altering it from its true state88“Some of the clips had a kind of "buzz" vibrating sound that other clips of the same piece didn’t.” (P4)
1.1 AmplitudeGeneral presence of distortion or clipping50“A lit bit of distortion made the sound a little fuzzy.” (P43)
1.2 SpectrumEnhancement or diminution of frequency bands in the music27“…cutoff on highs - some tracks specifically those with live instrument seemed washed out/underwater when distorted (Take That).” (P16)
1.3 Vocal ClarityEnhancement or diminution of the vocal in the music8“Sometimes the voice become clearer, purer.” (P54)
1.4 ArrangementAddition or removal of instruments or musical components in the music3“…choosing the wrong instruments in some clips, like horns. etc.” (P83)

2. NoisePresence of additional sounds that are not desirable32“Very much 'white noise' - sometimes 'echoy'. Some sounded like a record rather than digital.” (P60)
2.1 UnwantedGeneral hiss, popping, cracking, etc., being present29“Noise could be heard in the background of some clips.” (P05)
2.2 EchoesDelay or reverberation effects that are noticeable or not in the true state of the music3“Echoy sic noises” (p91)

3. TimingTemporal anomalies in the audio, where sequences or timing is not correct29“Clip 6 of one of the tracks seemed to "jump" and repeat.” (P18)

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