Learning Exercise

Consonant acoustics

Topics covered in this lab include fricative turbulence, plosives, burst range, nasals, liquids and glides.
Course: Speech & Hearing Science

Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems.... see more


Lab 7: Consonant Acoustics Vocal acoustics A. Concepts to work with 1. acoustics of consonants a. nasals b. stops c. semivowels d. fricatives 2. Spectral analysis reading B. Consonant acoustics 1. Turbulence: Using Audacity, record /sha/, /sa/, /fa/ in track 1. On the left side of the recording change the view to spectrogram. (Cut and paste this spectrogram into your lab as we have done before.) Then at the upper left corner of the Audacity screen, choose the Selection Tool. Select a segment of each fricative and then click on Analyze from the top bar menu, then Plot Spectrum. Cut and paste these spectrum pictures into your lab under the full spectrogram. What are the differences between fricatives in terms of the frequencies at which the spectral energy is strongest? This will be a range of frequencies. (Energy at the lowest frequencies is probably room noise, so focus on where the energy increases from a low point.) How does the point of constriction for each fricative cause the differences? Label your pictures. 2. Blockage of sound and release: a. Record /ata/ and /ada/ in Track 2. Change the recording to the spectrogram view. Magnify the picture with the magnifying button, and pull the bottom of the picture down if you want a larger view. Measure VOT in msec by dragging the cursor across the space between the two vowel energy masses (where it stops being red). When you cut this picture to paste it into your lab, be sure to include the time bar. b. Measure burst frequency range in Hz by selecting the burst and clicking on Analyze, Plot spectrum. How are the two energy bursts different? /t/ VOT /d/ VOT /t/ burst range /d/ burst range c. Record /ama/ and /aba/ and compare them. Do the same with /ana/ and /ada/. Paste the recording into your lab. What are the similarities and differences (energy, frequency, formant transitions)? Why are they different? Why are they the same? 3. Record /ala/, /ara/. Paste them into your lab. What are the differences between the two consonants? Focus on the formants! 5. Record /ji/, /ju/, /wi/, /wu/. Paste them into your lab. How do these glides differ in how they connect to the following vowel? Why?


Recording in Audacity, screen capture


Fricatives, plosives, nasals, liquids and glides.

Learning Objectives

Students will: 1. identify the frequency spectra of the fricatives 2. measure VOT 3. measure burst frequency range 4. compare & contrast /m/ & /n/ with /b/ and /d/ 5. compare /l/ and /r/ 6. compare /j/ and /w/