Homework 1: Articulatory and Acoustic Phonology
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CS 224S/LINGUIST 281 - Winter 2007
Homework 1: Articulatory and Acoustic Phonology |
| Due: January 16 at 9:59am, i.e. the start of class. |
Please read this entire page before beginning.
For these exercises, you may work in groups. Non-native speakers will probably need to team up with a native speaker. But do your write-ups separately, as discussed in the Homework Collaboration Policy
(1.1) Call the "TellMe" speech recognizer. The number is 1-800-555-TELL. Try at least two different kinds of questions (stock quotes, travel, etc). Try to "barge in" (i.e. talk while TellMe is talking to you). Write down any errors or misrecognitions that occur.
(1.2) Call the United Airlines automatic flight information, at 1.800.824.6200. Ask about a flight. Again, write down any errors or misrecognitions that occur.
(1.3) Go to one of the TTS demo sites, ATT or IBM. Test out the site by choosing at least seven different sentences (paste them from another web site, or make up things). Try to be creative, including questions, exclamations, or whatever. Try at least two different voices. (You may have to choose "Download wav file" and play it twice, if the speech sound gets cut off as it plays the first time while it downloads.). Write down at least 5 errors that you hear; note whether these errors are in the phones, in the intonation/prosody, or something else.
(1.4) Find and correct the mistakes in the ARPAbet transcriptions of the following words:
(1.5) Transcribe the following words into the ARPAbet.
(1.6) Transcribe the following three wavefiles at the word level (that is, write down the words that occur in the utterance). Make sure to listen to them carefully and more than one time. I've given them in various format; if you have trouble listening to them, let me know immediately.
(1.7) Now open all 3 files in Praat, the speech analysis program we used on class on Thursday January 11. Transcribe all 3 files into the ARPAbet, using Praat to help you play pieces of each wavfile, and to look at the wavefile and the spectrogram. (In fact, you can use Praat to play the files for exercise 1.3 as well). Turn in both the ASCII ARPAbet sequence (just type it into your homework answers) and also include a picture of Praat labeled file from the "Draw" window as we saw in class (if the file is too long to read the fonts clearly in the "draw" window, just break it into 2 or 3 parts and attach separate pictures). This is very hard, so I don't expect you to be perfect, I just want to you try to listen carefully for what's happening in each file.
(1.8) Get the minimum and maximum pitch for the first 5 seconds of each of the three files. Record the pitch range (range = max - min).
(1.9) What are some differences between the Boston News file and the two Switchboard files, in terms of transcription differences, pitch range, or other things you noticed. Switchboard is human-human speech; Boston News is broadcast speech, which resembles human-machine speech. Could this play a causal role in the differences you found? How?
You may use an on-line ARPAbet dictionary to help you. Here is the CMU dictionary. But many or most words in the above sentences will not be the same as they are in the dictionary! So be careful not to just copy the pronunciation from the dictionary (besides the fact that CMU uses a slightly different version of the ARPAbet than the one in the slides from lecture 1)
Getting Praat: Praat itself is here, and is free and very simple to download, just grab the executable. It runs on most popular platforms.
A quick Praat intro, written by Edward Flemming, is here.
A longer Praat tutorial is here.
How to turn in the homework:
lastname_firstname_hw#.pdf