Using Music for PEAQ
We suggest using a library of music files that provides good results for PEAQ and that can be used repeatedly to provide consistent results ensuring that changes in the values reflect only changes in the quality of the Device Under Test (DUT).
Both rock, pop, and classical music can be used as reference files. You can indulge your eclectic taste in music. In connection with the cognitive model in a western classical music tradition, it may be useful to choose music that principally contains tones that are consistent with “Concert A”, the reference used to tune an orchestra 440Hz (cycles per second) in order to present pitch familiar to the golden ear.
Alternatively, eastern music does not use this system. For example, Indonesia has a diversity of culture and the intonation of the instrument is determined by the materials they are made of, such as gamelan. The cognition of the golden ear used for subjective testing takes this into account.
I prefer classical music that contains a sample ranging from full orchestra down to a single instrument such as a flute which has a relatively simple tone producing a small number of harmonics. Full orchestra music with lots of symbols can emulate white noise and therefore mask some of the impairments.
Old faithful – Vivaldi Four Seasons
- (or Quattro Stagione) for pizza lovers
Stravinsky – The Rite of Spring
- Caused a riot at its first performance in 1910 so hopefully, it won’t distract you too much from your testing
Dvorak – Symphony No.9 New World Symphony
- Great range, the 2nd movement (Largo) is a simple Cor Anglais solo followed by many full orchestra passages
Hans Zimmer – Gladiator
- If you are not doing a public performance, copyright rules should not apply but please check to be sure. To paraphrase Maximus Decimus Meridius, “what we do in this audio test session echos in eternity”.
Debussy – Clair De Lune
- Simple & divine piano music, well known (allows listener to discriminate pitch and tempo impairments)
Bedrich Smatana – Vltava Symphonic Poem (or die Moldau, in German)
- Evokes the story of the river starting with simple flute music and developing into rapidly moving full orchestra
We extract approximately 10 seconds in order to provide a clip of music long enough in duration for a human to determine an opinion about the quality of the audio clip. This opinion is called the Mean Opinion Score (MOS). All clips should be at least 48k samples per second with 16bits of vertical voltage resolution.
Sample Audio Files
Below is a link for you to download sample reference files. They all score well with PEAQ (4.5 or better) on a back-to-back balanced connection through the DSLA. They have all been resampled to mono 48k and saved as 16-bit PCM files with lengths of around 30 seconds. The files are listed as having a royalty free license.
- Easy Listening – Piano (WTGT.WAV)
- Drama & Film Score – Orchestra (UV.WAV)
- Rock – Electric Guitar (MV.WAV)