S302, Kewley-Port 11/5/07

Homework 11
Open/closed tubes, Communication, IPA, Phonation

1. a) Consider a longitudinal standing wave in an open-closed tube, L =  17 cm (the average length of a male vocal tract). Draw a standing wave in the tube in the 1rst mode of vibration. Label all the nodes and antinodes.

b) The speed of sound in air is 320 m/s. What is f0? What are the frequencies of the first three modes of vibration, F1, F2 and F3?

c) What is the wavelength for first mode of vibration? For the 2nd mode of vibration?

d) Explain why this is called a 1/4 wavelength resonator

2. Look at Fig. 1 in the speech chain. Explain why the book says that in normal communcation there are "two listeners, not just one".

3. Define "phoneme", and explain how they are combined into syllables and words.

4. In the IPA discription of cosonants, the table is arranged with three primary dimensions. Describe each of these three, and give an example of two phonemes that contrast in along that dimension (e.g, /b/ and /d/ have differ on the dimension XX because one is "bilabial" and ....)

5. According to the IPA vowel quadrilateral, what are the three phonetic features that specify these 3 vowels?

/i/ ,     /a/ (English "ah"),   and     /u/

6. Explain the relation between the resonance of a system and the amplitude and frequency of a forced vibration impressed on the system.

7. a) How does the Speech Chain describe Fourier Analysis? (b) The output of Fourier Analysis is an amplitude spectrum, such as shown in Fig. 3.14. Describe in your own words differences you see between the spectrum of the /a/ and the /uh/ vowels shown in Fig. 3.15.

8. The larynx causes the airflow from the lungs to break into puffs of air. (a) Physiologically, what happens in the larynx to cause the puffs? (b) Draw a waveform showing what the shape of these airpuffs. Describe in words what this shape looks like.

9. According to the Chapt. 4 phonation reading, F0 can be affected by four different processes. Explain what these four processes are and how the affect F0 in your own words.