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１．日 時　　　平成２１年３月１２日（木）１５：３０〜１７：３０

２．場 所　　　情報科学研究科講義棟　大講義室

３．講演題目　　 「Estimating vocal-tract length from syllable phrases
and revising the definitions of pitch and timbre to reflect our
perception of speaker size and musical instrument size」
　　　　　　　
４．講 演 者　　　Dr. Roy D. Patterson
Head of the Center for the Neural Basis of Hearing, Department
of　Physiology, Development and Neuroscience, University of Cambridge

５．講演要旨
The sounds that animals use to communicate (including the sounds of
speech and music) have a very special pulse resonance form which
automatically distinguishes them from the background sounds made by wind
and waves. The parts of the body used to produce pulse-resonance sounds
grow as the animal grows, and as a result, the `acoustic scale' of these
sounds increases with body size. The size variability in communication
sounds poses a serious problem for speech recognition machines, but
humans and other animals, seem to be able to hear the message no matter
what the size of the source. The first part of this talk is about the
size information in communication sounds and how the auditory system
extracts this information from short segments of sounds like vowels and
musical notes.
The second part of the talk is concerned with the relationship between
acoustic scale (AS) and timbre in speech sounds. Specifically, it is
concerned with what happens as a speaker increases in size. Imagine the
spectrum of the sound plotted on a logarithmic frequency axis. As a
child matures, their vocal folds vibrate more slowly and the harmonics
of f0 move, as a unit on the log axis, towards the origin. The position
of the fine structure specifies the AS of the glottal excitation.
Similarly, the child’s vocal tract lengthens and the envelope moves
towards the origin, without changing shape on the log axis. The position
of the envelope specifies the AS of the vocal tract filter. The standard
definition of timbre implies that a shift in the position of the fine
structure does not change the timbre of the sound (although it
eventually turns the child into a dwarf), whereas the shift in envelope
position does change the timbre (eventually turning the child into a
counter tenor). Note that both of these AS manipulations produce
substantial changes in the relative amplitudes of the harmonics. If the
fine-structure shift is accompanied by an equivalent envelope shift, the
child eventually becomes a man, and the relative amplitudes of the
harmonics do not change.
These observations suggest that the definition of timbre would be more
useful if it explicitly recognized the role of AS in perception, and
treated both of aspects of AS in the same way, with regard to the
definition of timbre. That is, the effects of changes in the AS of the
fine-structure and the AS of the envelope scale should both be either
included or excluded from the definition of timbre.
Research supported by the UK MRC


６．講演者略歴　
Roy D. Patterson was born in Boston, MA, on 24 May 1944. He received a
B.A degree from the University of Toronto in 1967, and a Ph D. from the
University of California in 1971, on residue pitch perception. From
1975-1995, he was a research scientist for the UK Medical Research
Council, at their Applied Psychology Unit (15 Chaucer Road, Cambridge,
England), focusing on the measurement of frequency resolution in the
human auditory system, and computational models of the auditory
perception. He also designed and helped implement auditory warning
systems for civil and military aircraft, railway maintenance equipment,
the operating theatres and intensive care wards of hospitals, and most
recently, fire stations of the London Fire Brigade.
Since 1996, he has been the head of the Centre for the Neural Basis
of Hearing in the Department of Physiology, Development and Neuroscience
at the University of Cambridge, UK. The focus of his current research is
an ‘Auditory Image Model’ of auditory perception and how it can be used
to 1) normalize communication sounds for glottal pulse rate and vocal
tract length, and 2) produce a size-invariant representation of the
message in communication sounds at the syllable level. Dr Patterson is a
Fellow of the Acoustical Society of America and has published over 100
articles in JASA and other international journals. See
http://www.pdn.cam.ac.uk/groups/cnbh/ Some of the more recent articles
from the CNBH are listed below.
Dr Patterson has been a visiting researcher at several prominent
laboratories in Japan over the past 20 years, including ATR HIP, NTT
BRL, NTT Keihanna (Cslab), and Nagoya Univ. Engineering Dept (CSAIR).

　

７．担当教員　情報科学研究科
　　　　　　　教授　赤木　正人（内線：1236）

８．問合せ先　総務課共通事務係
　　　　　　　情報科学研究科担当　山崎（内線1156）

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We would like to inform you about the 16th IS-Seminar as follows.

DATE: March　12, 2009 15:30-17：30
PLACE: IS Lecture Hall
SUBJECT: "Estimating vocal-tract length from syllable phrases and
revising the definitions of pitch and timbre to reflect our perception
of speaker size and musical instrument size"
SPEAKER: Dr. Roy D. Patterson
Head of the Center for the Neural Basis of Hearing, Department
of　Physiology, Development and Neuroscience, University of Cambridge　
SPEECH: English
REFERENCE: Administrative Services Office (E-mail: is-secr)