•In order to perform
the measurements the test signals were put on the digital audio players using the best codec available for each device
(uncompressed wav when available).
The formats employed are the following:
•
•Uncompressed WAV (44100 Hz, 16 bits, stereo)
•WMA Lossless
•WMA 192 kbps
•WMA 128 kbps
•MP3Pro 144 kbps
•MP3 192 kbps
•MP3 128 kbps
•Apple Lossless
•AAC 192 kbps
•AAC 128 kbps
As the difference between the same recording in
different formats is very subtle, and does not usually require that the user
adjusts the playback gain, we discarded the fact that different file formats
were employed on different devices.