Homelab 6

In this homelab you will measure the frequencies of vocal formants.

Step 1 Read Chapter 22 of Hartmann. It is essential to understand the difference between formant frequencies and the frequencies of harmonics of the fundamental.

Step 2 Using Raven Lite, record yourself saying eeeeooooeeeeoooo. The eeee vowel sound should be like in the word 'seat' and the oooo sound should should be like in 'soon'. Spend a few seconds on each vowel and vary your voice continuously from the eeee sound to the oooo sound. Now make adjustments to Raven Lite so that the formats are visible. I found that a frequency range from 0 to 5 kHz works well, and that the formats were more visible with a relatively low setting of 700 for the focus. I also reduced the contrast to 30. As indicated in Table 22.1 of Hartmann, you should find that the first formant does not change much between eeee and oooo, but that there is a large change of the second formant frequency. The second formant frequency is easier to observe and measure than the first one, both because it changes more and because it is at a higher frequency. Measure your second formant frequency for oooo and eeee, and then make the same measurement for at least two other people.

Step 3 Make a plot of your results on this form. Plot the frequency along the y-axis, using a scale that goes from 0 Hz up to a suitable maximum value that will include all of your data. Label the y-axis "Second Formant Frequency (Hz)". Label the x-axis "Subject Number" and use integers 1, 2, 3, ... for the scale on the x-axis. Space them evenly and assign one integer to each of your subjects. Plot the value of each subject's eeee and oooo second formant frequency above each integer. Use a black dot for the eeee frequency and an open circle for the oooo frequency. Add a key to the plot somewhere on the grid where there is unused space. Draw your black dot symbol and write "eeee" next to it. Beneath the dot draw your circle symbol and write "oooo" next to it. Try to make all of your plotting symbols (dots and circles) uniform so that it is clear that they refer to the same kind of information everywhere on the graph. Scan your homelab to a pdf file using a scanner or a smartphone app, and upload it to the dropbox on our Canvas site before it is due.