1996 SALS-SIG Seminars
SALS-SIG Research Seminar
Classification of Fricative Spectra - the problem of [f] and [T]
Speech, Hearing and Language Research Centre, Macquarie University
When: Friday, 13th September 1996
Where: Room E6A357, Macquarie University
English has four places of articulation for fricative consonants: the labio- dental /f/, the dental /T/, the alveolar /s/ and the alveolopalatal /S/. The first two are referred to as non-sibilants - they have a flat spectrum and very low energy levels compared to the neighbouring vowels. The last two are referred to as sibilants, and have prominent spectral peaks and very high energy levels relative to the neighbouring vowels. Traditionally, it has been a lot easier to classify the sibilants using acoustic parameters than it has to classify the non-sibilants, due to their relatively flat spectrum below 10 kHz (the spectral range used in most speech research).
The work I'll be presenting looks at the spectral range above 10 kHz, up to 20 kHz, since consideration of articulatory-to-acoustic mapping criteria suggested that there may be spectral information in that range. We used pre-emphasis to boost the higher frequencies of the spectrum (by 6 dB / octave), and also explored the differences between taking averaged FFTs across the entire fricative token, and taking a single FFT at the token midpoint. Results suggest that although the techniques we employed were useful in helping to classify [f] and [T] correctly, the percentage of correct classifications was not as high as for the sibilant fricatives [s] and [S].
This work was done in collaboration with Catherine Watson at the Speech, Hearing and Language Research Centre at Macquarie University.
|Last modified: July 1997|