Linguistics 520: Linguistic Phonetics
UNC-Chapel Hill Linguistics
Fall 2026
Elliott Moreton

Week 4, Day 10: 2026.09.09 (Wednesday)

Topics: Source-filter model: Perturbation theory of non-schwa articulations. Height and backness; F1 and F2.

Class:

• Brief recapitulation of perturbation theory (slides, Canvas)
• Height
  • Articulation (mirror demo)
  • Predicted acoustic effect of oral vs. pharyngeal constriction on F1
  • Acoustic consequences of pinching a flexible tube
  • Psychological effect of F1 on perceived vowel quality: F1 varying through schwa. F1 varying through [i].
• Backness
  • Articulation (spaghetti demo)
  • Predicted acoustic effect of front vs. back oral constriction on F2
  • Acoustic consequences of pinching a flexible tube
  • Psychological effect of F2 on perceived vowel quality Synthetic demo of F2 being varied: With F1 low. With F1 middling. With F1 high.

Assignments:

• For 9/14 (M) (Day 12): HW 2 (Canvas)
• For 9/23 (W) (Day 15): Do the on-line human-subjects training (do the CITI modules for Social and Behavioral Research)

Week 3, Day 9: 2026.09.04 (Friday)

Topics: Source-filter model: Perturbation theory of non-schwa articulations. Rounding

Class:

• Mapping the uniform tube onto vocal-tract landmarks (slides, Sakai)
• Vowel articulations (slides, Sakai)
  • Rounding
    • Articulation: mirror demo
    • Predicted effect on F1? F2? F3?
    • Audio demo: Buzzing lips into 17.5-cm tube, then pinching the open end. What should happen to the formant frequencies?
    • Audio demos: Lowering schwa formants by 20%; Lowering [i] formants by 20%.
  • En passant: Demonstrate wide-band spectrograms (window length = 0.005 s). Could help with HW 2!
• Trip to soundproof booth in Dey 103. The sign-up sheet is here.

Assignments:

• For 9/09 (W) (Day 10): Bring a mirror to class
• For 9/14 (M) (Day 12): HW 2 (Canvas)
• For 9/23 (W) (Day 15): Do the on-line human-subjects training (do the CITI modules for Social and Behavioral Research)

Week 3, Day 8: 2026.09.02 (Wednesday)

Topics: Recording. Partnership assignments

Class:

• Where we're headed: Vowels beyond schwa, illustrated with a practical homework (preview on Canvas).
• HO: How to record with Praat (Canvas)
  • A pretty good recording, vs. a pretty bad one. The difference isn't easy to hear, but you can see it clearly in Praat.
  • A recording where the speaker blew on the microphone (first utterance) vs. one where the microphone was correctly placed.
  • A recording illustrating peak clipping, vs. one where the recording level was correctly set
• Partnership assignments
• Go over HW 2 assignment (preview on Canvas)
• You can sign up here for the soundproof studio in Dey 103.

Assignments:

• for 9/4 (F) (Day 9): Read Ladefoged & Disner Ch. 12 ("Making English vowels"). This will introduce the ways in which the uniform schwa-like vocal tract can be perturbed.
• For 9/4 (F) (Day 9): Read Ladefoged & Disner Ch. 5, "Charting English vowels". Bring mirrors!
• For 9/14 (M) (Day 12): HW 2 (Canvas)
• For 9/23 (W) (Day 15): Do the on-line human-subjects training (do the CITI modules for Social and Behavioral Research)

Week 3, Day 7: 2026.08.31 (Monday)

Topics: Nodes and antinodes in the uniform tube.

Class:

• Nodes and antinodes: What they are, and why they matter.
• Demonstration with actual tube, and simulation (W. Fendt).
• Partnership questionnaire (5 mins.)

Assignment

• For 9/2 (W) (Day 8): Bring computers to practice recording
• For 9/4 (F) (Day 9):Read Ladefoged & Disner Ch. 12 ("Making English vowels"). This will introduce the ways in which the uniform schwa-like vocal tract can be perturbed.

Week 2, Day 6: 2026.08.28 (Friday)

Topics: Resonances of a half-open tube.

Class:

• Reprise:
  • Source/filter model of vowel production
  • Last time's experiment: The response curve of the tubular filter, with peaks (formants) at particular frequencies
• Why do the peaks occur at those particular frequencies? (handout, also on Canvas, with audio)
• Destructive and constructive interference
• Resonant frequencies: F1, F2, F3, ...

Assignment:

• For 8/31 M (Day 7): Read Johnson Ch. 6 Section 2 on the acoustic theory of vowels. (Warning: May not be easy. Start early!)
• For 9/2 W (Day 8) Read Ladefoged & Disner Ch. 12 ("Making English vowels"). This will introduce the ways in which the uniform schwa-like vocal tract can be perturbed.
• For 9/2 W (Day 8): Bring a computer to practice recording.

Week 2, Day 5: 2026.08.26 (Wednesday)

Topics: Source/filter model: Filtering effect of a half-open cylinder

Class:

• Reprise of source-filter model. Last time: Source.
• This time: filter (slides on Canvas)
• Demonstration: Resonances of a half-open cylinder (i.e., [ə]) ( audio).
• Observe filtering effect of tube
• Return HW 1.

Assignment for 8/28 F (Day 6):

• Read Johnson Chapter 2, Section 4, on resonance and schwa

Week 2, Day 4: 2026.08.24 (Monday)

Topics: Source/filter model: Acoustics of the laryngeal source. Use of the laryngeal source in languages.

Class:

• Go over HW 1. Don't forget:
  • Honor Code statement ("I completed this work in accordance with the UNC Honor Code").
  • Names of collaborators.
  • Draw box around notes added in class (or mark in some other clear way)
• Thought problem from last time: Predict narrow-band spectrogram of a glissando (rising or falling sinusoid)
• Finish slides (on Canvas): Source-filter model 1. How is the laryngeal source used to make contrasts in natural languages?

Week 1, Day 3: 2026.08.21 (Friday)

Topics: The source-filter model of vocal production. The larynx and phonation. f0. The glottal wave.

Before class: Please open all three of the Homework 1 sound files in Praat (the two that are included in the zip file, and the one that is on the Ladefoged and Disner site).. If something isn't working, please call me over.

Class:

• Slides (on Canvas): Source-filter model 1.
• Demonstration of acoustic filtering by half-open tube: Low-tech source-filter synthesis: Buzzing lips, then buzzing lips into 17.7-cm tube.
• Source: The larynx (vocal-fold vibration)
• Anatomy of the larynx
• Acoustics of the unfiltered glottal wave
  • Synthesized glottal wave, f0 = 100 Hz
  • Synthesized glottal glissando.
• Start on HW 1.

Assignment for 8/24 (M):

• Finish HW 1.
• Read Johnson 2.1 (voicing), 2.3 (vocal-tract filtering).
• Listen to the Glottal glissando and think about what the spectrogram ought to look like.

Week 1, Day 2: 2026.08.19 (Wednesday)

Topics: Using Praat. Sound. Spectrograms.

Class:

• Types of sound wave (example)
• Simple periodic waves:
  • Physically simple ( simple harmonic motion)
  • Psychophysically simple (stimulate one point on the basilar membrane)
  • Mathematically elementary (in Fourier analysis)
• Praat:
  • Using the Edit function to listen and look (helpful handout from Jen Smith is here).
  • Measuring frequency and period; calculating wavelength
  • Spectrogram basics (like reading music).
  • Use of Spectrogram:Spectrogram settings... to change the Analysis Window: wide-band (0.005 s) and narrow-band (0.05 s)
  • Use of Spectrogram: View spectral slice to make a power spectrum
• Complex periodic waves.
• Fundamental frequency.
• Start on HW 1.

Assignment:

• For 8/21 F: Read Ladefoged & Disner Ch. 2, on pitch and the larynx.
• For 8/24 M: Do HW 1, making some basic acoustic measurements and calculations. The Ladefoged and Disner website is here. An alternative website for the Ladefoged/Disner audio is here.

Week 1, Day 1: 2026.08.17 (Monday)

Topics: Course organization. Praat. Intro to sound.

Class:

• Go over syllabus and course information (Canvas).
• Praat sound analysis software.
  • Information on Installing Praat, and more Praat resources (Jen Smith).
  • How to download sound files and open them in Praat (HO, Sakai). Example:
    • Right-click (control-click) on the link to this demo file.
    • From the resulting pop-up menu, save the file to disk. (Even if the menu calls the sound file a "video".)
    • Open it in Praat.
• The website that goes with the Ladefoged & Disner textbook. If it is down for some reason, here is an alternative with the same content.
• Intro to sound
  • Sound waves are air-pressure waves.
  • (Most) microphones are like little barometers.
• Using the Praat Edit function to listen and look (helpful handout from Jen Smith is here).
  • The waveform display. The time cursor. Zooming. Selecting an interval.
  • Configuring the waveform display with View: Show analyses... to turn off extraneous information.

Assignment for Day 2, 8/19 (W):

• Read Johnson Chapter 1, Sections 1--3, also on sound.
• Check that you can listen to and download sound files from the Ladefoged & Disner website . Navigate in that site to find an audio example, and click on it. You should hear something. In the media pop-up window, right-click on the Play/Stop button, and choose "Download video as..." to save the audio file in .aiff format
• Install Praat on your computer and check that it runs.
• Bring laptops to class next time with Praat installed!
• On the "Discussions" area in Canvas, please go to the "Introductions" discussion and post to it according to the instructions found there.