Ling 600.01 Phonetic Theory
The data: The raw data for this lab will come from a perception experiment that uses audio recordings of fricatives in CV syllables as stimuli. On each trial, you will listen to a pair of such stimuli and judge the degree of similarity between the two stimuli on a five-point scale ranging from "same syllable" (at one end) to "very different" (at the other). These judgments will be the basis for a multi-dimensonal scaling analysis that will be part of the data for take-home exercise 4.
Before class: Get the sibilantMDS.zip file from the the MDSresults subdirectory of our class page, and unzip it. This contains the audio files and the praat script that you need to run the perception experiment. Open up the script in Praat, rename the ExperimentMFC object with your name, and then run the experiment. Be sure to be ready for the first pair, since there are no practice items.By the beginning of class: Once you have finished making the 125 judgments, collect the results into a Table object and write out the Table to a yourname.Table file. Upload the yourname.Table file to the "Results of the fricative similarity judgment experiment" dropbox on the Carmen site for our class.
In class: What we will do in class is work through the steps of doing a multi-dimensional scaling analysis, to reduce the 125 judgments to a perceptual map with fewer dimensions, like the ones described in Sections 5.4, 6.6, and 7.5 of Johnson (2011). We will also collate your responses with your classmates' responses to make a group map, which will be part of the processed data that you will be analyzing for take-home Exercise 4.
Final report: Your final report will be a short "Methods" section for your writeup of the Multi-Dimensional Scaling exercise (Exercise 4).
Optional follow-up: You may decide after looking at the maps from your responses and your classmates' responses that you would like to ask your language consultant to also be a subject in this experiment. If you do so, and would like us to include the language consultant's data in the group map, upload that Table file to the dropbox, too.