Week 16, Day 42: 2026.12.02 (Wednesday)

Week 16, Day 41: 2026.11.30 (Monday)

Week 15, Day 40: 2026.11.23 (Monday)

Week 14, Day 39: 2026.11.20 (Friday)

Week 14, Day 38: 2026.11.18 (Wednesday)

Week 14, Day 37: 2026.11.16 (Monday)

Week 13, Day 36: 2026.11.13 (Friday)

Week 13, Day 35: 2026.11.11 (Wednesday)

Week 13, Day 34: 2026.11.09 (Monday)

Week 12, Day 33: 2026.11.06 (Friday)

Week 12, Day 32: 2026.11.04 (Wednesday)

Week 12, Day 31: 2026.11.02 (Monday)

Week 11, Day 30: 2026.10.30 (Friday)

Week 11, Day 29: 2026.10.28 (Wednesday)

Week 11, Day 28: 2026.10.26 (Monday)

Week 10, Day 27: 2026.10.23 (Friday)

Week 10, Day 26: 2026.10.21 (Wednesday)

Week 10, Day 25: 2026.10.19 (Monday)

Week 9, Day 24: 2026.10.14 (Wednesday)

Week 9, Day 23: 2026.10.12 (Monday)

Week 8, Day 22: 2026.10.09 (Friday)

Week 8, Day 21: 2026.10.07 (Wednesday)

Week 8, Day 20: 2026.10.05 (Monday)

Week 7, Day 19: 2026.10.02 (Friday)

Week 7, Day 18: 2026.09.30 (Wednesday)

Week 7, Day 17: 2026.09.28 (Monday)

Week 6, Day 16: 2026.09.25 (Friday)

Human-subjects training due.

Week 6, Day 15: 2026.09.23 (Wednesday)

Week 5, Day 14: 2026.09.18 (Friday)

Week 5, Day 13: 2026.09.16 (Wednesday)

Week 5, Day 12: 2026.09.14 (Monday)

HW 1 due

Week 4, Day 11: 2026.09.11 (Friday)

Perturbation theory: height and backness

Week 4, Day 10: 2026.09.09 (Wednesday)

Perturbation theory: rounding

Week 3, Day 9: 2026.09.04 (Friday)

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

Class:

• Mapping the uniform tube onto vocal-tract landmarks
• 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) (next time): Bring a mirror to class
• For 9/11 (M) (two times from now): HW 2 (Canvas)
• For 9/18 (F): 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:

• Return HW 1. Comments:
  • Erroneous answers to #2b ("420 Hz") caused by taking spectral slice of a selection that was much shorter (0.004 s) than the spectral analysis window (0.05 s). It's best to take the slice at a point and leave the windowing to Praat.
  • Precision: In phonetics, precision of 1 Hz or 1 ms is about as good as it gets. Extra decimal digits are meaningless and can be omitted.
• Where we're headed: Vowels beyond schwa, illustrated with a practical homework (next time).
• 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
• Sign up here for the soundproof studio in Dey 103.
• Partnership assignments
• Go over HW 2 assignment

Assignments:

• For 9/4 (F) (next time): Read Ladefoged & Disner Ch. 5, "Charting English vowels". Bring mirrors!
• For 9/9 (W) (time after next): HW 2 (Canvas).
• For 9/18 (F) 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) (next time):

• Read Ladefoged & Disner Ch. 12 ("Making English vowels"). This will introduce the ways in which the uniform schwa-like vocal tract can be perturbed.
• Bring computers to practice recording

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 on Canvas, with audio)
• Destructive and constructive interference
• Resonant frequencies: F1, F2, F3, ...
• Source-filter independence: Please listen to the following two sound files. Without looking at the spectrogram, which is changing in each file: formants or harmonics?
  • Schwa glissando
  • Diphthong

Assignment:

• For 8/31 M (next time): Read Johnson Ch. 6 Sections 1 and 2 on the acoustic theory of vowels. (Warning: May not be easy. Start early!)
• For 9/2 W (time after next) 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 (time after next): 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).

Assignment for 8/28 F:

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

Week 2, Day 4: 2026.08.24 (Monday)

Topics: Source/filter model: 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)
• 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
  • Larynx atop trachea
  • Larynx in throat
  • Phonation in real time (movie from Edmonson & Esling 2006, on Canvas)
  • Control of frequency by stretching and relaxing vocal folds (J. Thomas, YouTube). (Note: This video is stroboscopic, so the vocal folds may look like they aren't vibrating.)
• 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)
  • 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.