Download Lab Guide: Constructing Materials with Praat & Audacity for Speech Processing - Prof. Elle and more Lab Reports Linguistics in PDF only on Docsity! LING499A Lab 4: Instructions for Material Construction Praat: http://www.praat.org Audactiy: http://audacity.sourceforge.net/ Ensure sure that you have the most (stable) versions of Praat and Audacity. You should use Praat to splice the sound files and Audacity to insert the white noise. 1) First open your sound file in Praat. 2) Your file will now appear in the Praat Objects Box. 3) Click on âEditâ to open the waveform of the sound file. Notice that there are a number of spoken âsentencesâ (SAY ____ AGAIN) in the file (each sentence is represented by an LING499A Lab 4: Instructions for Material Construction increase in the amplitude of the waveform). Highlight the middle sentence of the three that were spoken for each word. 4) Then click on the âSELâ in the bottom left hand portion of the window. Once youâve clicked on âSELâ you should have both the waveform and the spectrogram. 5) Then, by looking at the spectrogram and playing the sound file (using the TAB key to play the file), isolate the word between SAY and AGAIN. Make sure you get the whole word and nothing else. Once youâve selected the entire target word, save it to a WAV file. LING499A Lab 4: Instructions for Material Construction 11) Now, you want to select the syllable that you are interested in replacing with the âwhite noiseâ. You can click anyway where in the spectrum, and by dragging the mouse, you can select different portions of the file. In the example below, Iâve selected the second syllable. Be sure to select all of the syllable/sequence youâre interested and only the syllable/sequence youâre interested in. 12) Once youâve selected the portion of the file youâre interested in, click on GENERATE > White Noise. Remember to listen over headphones, and do your best to select only the portion that youâre interested in. LING499A Lab 4: Instructions for Material Construction 13) Then, a small dialogue box will appear that will display the amount of time for the noise youâre interested in inserting. Click on âGenerate Noiseâ. 14) You will now notice that a large band of white noise (sound at every frequency) has been generated over your selection (sometimes, it may look like it has generated noise to the left of your selection â donât worry, it hasnât. That just has to do with the resolution of the spectrogram. You can check this by viewing the waveform). LING499A Lab 4: Instructions for Material Construction 15) After youâre back in waveform view, go to EFFECT > Amplify, because we want to decrease the overall power of the noise â which for some reason, Audacity generates as being really loud. 16) Reduce the amplitude by 24 dB (move the slider to -24dB).
