ACTL
Course: Laboratory Phonology Homework 2
This file and the links can be found at
http://www.phon.ox.ac.uk/~jcoleman/ACTLhomework2.html
This homework assignment is to be completed and your measurement
workbook emailed to `Oiwi Parker Jones
(oiwi.parkerjones@ling-phil.ox.ac.uk)
by Monday 22nd January. You
should also contact `Oiwi if you have any problems or questions about
the assignment.
We will transfer the recordings made in the first practical from CD to
this website (see links below) on Monday 15th Jan. You should visit the
site on say the evening of the 15th or shortly after and download the
.wav file for the list you have been assigned to do.
Here's how to make the measurements.
1) If you haven't already done so, download and install wavesurfer from
http://www.speech.kth.se/wavesurfer/download.html.
2) Start wavesurfer by double clicking on it. Open your file, e.g.
list4.wav (File/Open, then browse for where you have downloaded it to).
3) In the "Choose Configuration" pop-up window, click on "Speech
analysis", and then OK. This gives four displays of the speech; from
top to bottom: 1) a (part of) the waveform; 2) a spectrogram of the
same section, with formant frequency measurements picked out in various
colours; 3) the f0
(pitch) track, for the voiced parts of the speech; 4) a slider for
moving backwards and forwards through the file. There are some buttons
at the top for playing the file if you want to listen to it.
4) You will need to configure the formant tracking so that it is done
with the same parameter settings as Richard Wright's experiment. Point
to the spectrogram window, RIGHT-click and choose Properties. Click on
the "Formants" tab. The number of formants should be 4, Analysis window
length should be 0.025 s, Analysis window type: Hamming, and LPC order:
12.
Repeat the following steps for each word in the list.
5) Using the slider, position the slider over the word, to roughly
place the vowel in the centre of the analysis window.
6) Carefully study the waveform and the spectrogram to identify the
vowel. The waveform will be loudest (i.e. biggest) near the centre of
the vowel. Vowels are voiced, so the spectrogram has vertical stripes.
Compare the vowel of the word to the example sheets I gave out in the
class. Remember that voiced sonorant consonants such as /w/, /j/, /r/,
/l/, /m/ and /n/ are also voiced and acoustically similar to vowels,
but they are quieter.
7) For the vowel of each word in the list, you need to make three
measurements: i) vowel duration (Vdur), ii) first formant frequency F1
in Hz (F1_Hz) and iii) second formant frequency in Hz (F2_Hz). The
latter two are to be made at the point of greatest displacement in the
vowel (usually the point where F1 is highest, since it goes up and down
for pretty much every vowel).
8) Duration. In the upper
(waveform) panel, point to the beginning of the vowel and click the
left mouse button. While still holding it down, move to the end of the
vowel and let go. At the bottom of the window various numbers are
given, including e.g. "length 00.273", which means the duration in
seconds between the two cursor positions. This is what you enter into
the spreadsheet.
How do you know where the vowel begins and ends? Between voiceless
consonants it is pretty obvious. Before and after voiced consonants,
look at the waveform and spectrogram to see where the signal changes
from quiet voicing to the louder voicing of the vowel. If you are still
unsure, it does not really matter, so long as you are consistent in how
you measure vowel duration.
9) F1 and F2. Look for the
loudest part of the vowel. For short vowels, this should be near the
middle. For long vowels it may be earlier (about 1/4 or 1/3 of the way
in). For diphthongs [ei] and [ou] we are only interested in the early
part of the vowel, where F1 is highest. To find where F1 is highest,
point at the F1 (red) formant track. In the numbers at the bottom of
the window, you should see something like "list1.frm" followed by some
numbers. The first number is the time where you are pointing. The next
number is F1 at that time and the following number is F2 at that time.
Move the pointer a little to the left and right near to where F1
appears to be highest and the vowel appears to be loudest, and see what
the maximum reading for F1 is. At that point, note down F1 and F2 in
the workbook. Ignore the decimals: for an F1 reading of 486.91, just
put 487 in the spreadsheet.
It helps to know what to look for. F1 values for vowels are in the mid
hundreds (e.g. 300-600 Hz), F2 values can be around 2000 Hz. Cruttenden
gives these values for British English, though of course they will be
different for different speakers and in different words. But it is
important to know roughly what to expect.
|
F1
|
F2
|
|
Male
|
Female
|
Male
|
Female
|
o
|
593
|
602
|
866
|
944
|
a
|
732
|
1011
|
1527
|
1759
|
first part of ai
|
734
|
822
|
1117
|
1275
|
first part of au
|
780
|
901
|
1368
|
1538
|
first part of ei
|
587
|
581
|
1945
|
2241
|
e
|
560
|
645
|
1797
|
2287
|
ii
|
275
|
319
|
2221
|
2723
|
i
|
382
|
432
|
1958
|
2296
|
first part of ou
|
537
|
545
|
1266
|
1573
|
^
|
695
|
813
|
1224
|
1422
|
Finally, if you are very unconfident about any of your measurements,
you can leave a gap in the workbook, but do let us know by email that
you have done so, so that we can take account of it.
Downloadable .wav files and Excel workbooks:
list1.wav
workbook1.xls
list2.wav
workbook2.xls
list3.wav
workbook3.xls
list4.wav
workbook4.xls
list5.wav
workbook5.xls
list6.wav
workbook6.xls
list7.wav
workbook7.xls
list8.wav
workbook8.xls