Exercises

Exercise 5.2. Record a sentence and analyse its pitch using cepstral_f0.c and autocorr_f0.c. Which method seems to be the more stable? Analyse the voicing of the same sentence using voicing.c. What are the upper and lower limits of your pitch range, during the voiced portions?

Exercise 5.3. Copy lpcana.c to lpcana2.c. Amend lpcana2.c so that it writes out lp rather than coeffs . Compare the lp files with some original audio recordings.

Exercise 5.4. Examine joe.dat (or another recorded signal) to determine the approximate location of each vowel. Write down the sample numbers of points approximately ¼ and ¾ of the way through each vowel. Use lpc_spectrum to estimate the first three formants of each vowel. Compare them to published tables of vowel formants, such as those in Olive et al. (1993).