LING 520
Introduction to Phonetics
Fall 2009

LAB 4: Vowel formants

Part I: Preparation

1. Recording:

The word list for recording is here. It includes the following words: beat, bit, bet, bat, hot, bought, good, boot, about. Read the word list three times: first, at a normal conversational speaking rate; then at a fast speaking rate; and finally at a slow speaking rate.

2. Readings:

1. Sidney Wood’s Online Praat tutorial, “Beginner’s guide to Praat” –> “spectral analysis”: http://person2.sol.lu.se/SidneyWood/praate/frames.html

2. Bill Labov, “Chapter 5.2, Accuracy and sources of error”, Principles of Linguistics Change: Social factors. (You can read it online through google book)

You need to know:

• How to locate the portion in a vowel that is least affected by neighbouring consonants?
• How to find the sampling frequency of a speech file?
• In LPC analysis, how to set the prediction order for male and female speech (Don’t forget that the frequency range in a signal is half of the sampling frequency)?
• How to measure formant frequencies?
• How to print and save a spectral image?

Part II: Plotting LPC spectra

Use your beat, boot, and hot in the normal speaking rate. Plot a LPC spectrum for each of the vowels in the words. State how you choose a point in the vowels to measure.

Part III: Measuring and plotting vowel formants

1. Measure the first two formants of the vowels in all three repetitions of the words for all speakers (Note that you only need to measure the schwa for the word about).

2. Average the formant frequencies of the three repetitions for each vowel and each speaker.

3. Plot the averaged formant frequencies on a formant chart (using this chart: http://www.phonetics.ucla.edu/course/chapter8/images/FormantChart.pdf, or using a software package such as R, Matlab, Excel, Praat, etc.), with x-axis showing F2 and y-axis showing F1 (on a log scale). Use colors and plot symbols to distinguish different speakers and vowels.

4. Average the formant frequencies of all speakers for each vowel and each speaking rate.

5. Plot the averaged formant frequencies on another formant chart. Use colors and plot symbols to distinguish different vowels and speaking rates.

6. Discuss what you find from 3 and 5. For example, what are the formant frequency variations among the speakers? Does speaking rate affect vowel formant frequencies? How?

The lab is due Oct. 28.