Perception of Data-Reduced Musical Instrument Tones

The Hong Kong University of Science and Technology
Department of Computer Science and Engineering


PhD Thesis Proposal Defence


Title: "Perception of Data-Reduced Musical Instrument Tones"

by

Mr. Chung Lee


ABSTRACT:

We know that musical instrument tones are recognizable even if they
are altered. The current study intended to investigate the perception
of musical instrument tones altered by one of the most popular
perceptual data reduction algorithm, MP3 compression. Eight musical
instrument tones were compressed using an MP3 codec to determine how
the detection of compressed sounds varies with bit-rate and
instrument. Sounds with harmonically-flattened frequencies were
compressed with bit-rates of 32, 40, 48, 56, 64, 80, 96, 112, 128, and
160 Kbps. Listeners were asked to discriminate the compressed sounds
from reference sounds resynthesized from the original data. Averaged
over the eight instruments, discrimination was very good (above 80%)
for bit-rates of 32 and 40 Kbps, moderate (above 70%) for 48 and 56
Kbps, and poor (around 50-60%) for bit-rates above 64 Kbps.
Statistical analysis showed that discrimination was significantly
affected by the instrument for intermediate bit-rates of 40, 48, 56,
and 80 Kbps. Discrimination scores were strongly correlated with the
signal-to-mask ratio (SMR) and spectral irregularity of the original
tone. Relative spectral error accounted for more than 80% of the
variance in the discrimination scores.


Date:                   Monday, 18 April 2011

Time:                   2:00pm - 4:00pm

Venue:                  Room 3405
                         lifts 17/18

Committee Members:      Prof. Andrew Horner (Supervisor)
                         Dr. Raymond Wong (Chairperson)
                         Dr. Jogesh Muppala
                         Dr. David Rossiter


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