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Qualitätsanalyse von Audiosignalen

Authors Kopel, C.
Year 2014
Thesis Type Bachelor's thesis
Topic Psychoacoustics
Abstract This Bachelor thesis examines the impact of levelling with regard to loudness and True Peak Levels in accordance with ITU-R BS.1770 and EBU R 128 on the audio data compression by MPEG-½ Layer II (MP2) and Layer III (MP3), applied in broadcasting. The introductory theoretical part therefore contains a critical summary of the topics loudness, levelling in broadcasting, and perceptual audio compression. In the succeeding parts of this paper, the design, procedure, and analysis of the practical experiment are described. For the experiment, reference test samples provided by the EBU as well as exemplary contributions to the radio programme of the WDR (public west German broadcasting corporation) were used. All samples were encoded on the one hand in original levelling, on the other hand levelled in accordance with EBU R 128. The sound quality impairment caused by the data compression was determined by means of PqevalAudio, a free implementation of PEAQ acording to ITU-R BS.1387. A comparison of the values measured showed that levelling in accordance with EBU R 128 has no negative impact on the sound quality of the audio compression and that, furthermore, with high probability, any positive impact cannnot be assumed either.
Supervisors Sontacchi, A., Berndt, C.