A comparative study of transforms for use in digital audio data compression

This paper provides a subjective quality analysis of transforms used in aud io compression algorithms for a class of music signals. A 34-subject listen er test compares three transforms in conjunction with an MPEG I layer 1 com pression scheme. One test compares the performances of the discrete wavelet packet transform (DWPT) and the modified discrete cosine transform (MDCT) used in MPEG. Another test compares the performances of a DWPT eight-level nonuniform critical-band split and a DWPT five-level uniform subband split. Results indicate that the critical-band split provides significantly bette r quality than the uniform subband split for sounds with tonal and strong l ow-frequency content, while the DWPT outperforms the MDCT with significant improvement for nontonal sounds. (C) 2000 Acoustical Society of America. [S 0001-4966(00)03907-2].