Dear Daniele,
Tim Ives wrote a robust routine for specifying the p-centers of
CV and VC syllables in 2005. It is described in
Ives, D. T., Smith, D. R. R. and Patterson, R. D. (2005). "Discrimination of speaker size from syllable phrases," J. Acoust. Soc. Am. 118 (6), 3816-3822.
The relevant text reads
The
syllables were normalized by setting the RMS value in the
region of the vowel to
a common value so that they were all perceived to have about
the same loudness. We
also wanted to ensure that, when any
combination of the syllables was played in a sequence, they
would be perceived
to proceed at a regular pace; an irregular sequence of
syllables causes an
unwanted distraction. Accordingly, the positions of the
syllables within their
files were adjusted so that their perceptual-centers
(P-centers) all occurred at
the same time relative to file onset. The algorithm for
finding the P-centers
was based on procedures described by Marcus (1981) and Scott
(1993), and it
focuses on vowel onsets. Vowel onset time was taken to be the time at which the
syllable first rises to
50 % of its maximum value over the frequency range of 300-3000
Hz. To optimize the
estimation of vowel onset
time, the syllable was filtered with a gammatone filterbank (Patterson
et al., 1992) having thirty
channels spaced quasi-logarithmically
over the frequency range of 300-3000 Hz.
The thirty channels were sorted in descending order
based on their
maximum output value and the ten highest were selected. The Hilbert envelope was
calculated for these
ten channels and, for each, the time at which the level first
rose to 50 % of
the maximum was determined; the vowel onset time was taken to
be the mean of
these ten time values. The
P-centre was
determined from the vowel onset time and the duration of the
signal as
described by Marcus (1981). The
P-center adjustment was achieved
by the simple expedient of inserting silence before and/or
after the sound. After
P-center correction the length of each syllable, including the
silence, was 683
ms.
Sincerely, Roy P
On 11/10/2016 15:41, SCHON Daniele wrote:
Deal all,
I wrote some Matlab code to automatically extract the perceptual centres from natural speech and I realized that there are several options and choices to be made.
I would appreciate your input on this topic (ie how you would generally proceed after speech-syllable segmentation) and I'll try to summarize the comments in a future post with my implemented solution(s) and the link to the code (with all the bugs!).
best
daniele
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Daniele Schon - Chercheur - INS INSTITUT DE NEUROSCIENCES DES SYSTEMESINSERM & Aix-Marseille Université - Timone - 27 BVD Jean Moulin - 13005 MarseilleTél: +33(0)4 91 38 46 32 / 55 77Site : https://sites.google.com/site/danieleschon/home - Email : daniele.schon@xxxxxxxxxxxAfin de respecter l'environnement, merci de n'imprimer cet email que si nécessaire.
-- Roy D. Patterson Department of Physiology, Development and Neuroscience University of Cambridge, Downing Street, Cambridge, CB2 3EG email: rdp1@xxxxxxxxx phone +44 (1223) 333819 http://www.pdn.cam.ac.uk/directory/roy-patterson http://www.pdn.cam.ac.uk/groups/cnbh/ http://www.AcousticScale.org