CA488 Speech Processing 2
Assignment 1, 2002/3
Introduction
Weight
This assignment is worth 35% of your module mark.
Submission
Details to follow.
Prosodic Analysis and Synthesis (25 marks)
Record your name in “darts-announcer” style: e.g. “My name is…” or “Hi! I’m…”. Make sure that your
intonation is of an “entertaining nature”.
Using Praat, segment the speech into phones. Measure the timings and duration of each phone.
Capture an estimate of the pitch track by approximating it as a series of straight lines. Note the timings of
each line and the F0 values at ech junction of lines.
Using the information you have gathered, create a synthetic version of your utterance using MBREdit.
There are 6 components to this submission:
1.
A screen shot of your original utterance as captured by Praat’s editor. This will show the speech
waveform, spectrogram, pitch track, and optionally formant tracks.
2.
A screen shot of your synthesised utterance as captured by Praat’s editor. This will show the
speech waveform, spectrogram, pitch track, and optionally formant tracks.
3.
A screen shot of your .pho file as seen from MBREdit’s editor.
4.
A .wav file containing a recording of your original utterance.
5.
A .wav file containing a recording of your synthesised utterance.
6.
A brief write up (no more than half a page), discussing anything of interest, e.g. difficulties
encountered, interesting results.
Vocal Tract Length Estimation (15 marks)
Record a schwah ([ ]). Attempt a number of vocal tract configurations close to what you consider a
schwa. Choose a segment where the formants are approximately evenly spaced. Estimate your vocal tract
length. Compare to some classmates. Note anything of interest.
Acoustic Phonetic Analysis of Vowels (60 marks)
Record the following English words in the context “Say … again”:
bead
bid
bayed
bed
bad
Boyd
bide
bod
bawd
bud
bood (rhymes with good)
booed
bode
bowed
You should obtain 5 recordings of each. Randomize your list and add extra ‘dummy’ utterances to avoid
list effects. Record your speech using 11kHz sampling rate with 16-bit precision mono. Set your recording
levels to avoid clipping or excessive quantisation noise. Recordings should preferably be made in a quiet
environment.
Your tasks are as follows.
Identify monophthong and diphthongs form the acoustics, i.e. not from what you expect yourself to
produce.
MONOPHTHONGS
1.
Measure F1, F2, F3 near the centre of the vowel. Also measure duration and average F0 values for
each of the vowels. Calculate the means and variances of your measurements.
2.
Plot –F1 (y-axis) against –F2 (x-axis) for each of the vowels (use different colours for neighboring
clusters). Also mark the mean. Consult with a classmate with a different accent. Note any differences.
3.
Plot F3, duration, F0 against the vowels. Note any patterns amongst/across tense/lax pairs, or
back/front vowels.
DIPHTHONGS
Measure F1, F2, F3 near the beginning and end of the diphthong. Estimate durations and average F0 of
each part of the diphthong. Plot –F1 (y-axis) against –F2 (x-axis) for each of the vowels (use different
colours for neighboring clusters). Also mark the mean. Join the first vowel point to the second using an
arrow. Consult with a classmate with a different accent. Note any differences.