Voice Quality + Korean Stops October 16, 2014

Don’t Forget! The mid-term is on Tuesday! So I have a review sheet for you. For the mid-term, we will just meet here. Today, we’re going to start working on an acoustic analysis of Korean stops. We still need to learn about one last measure of voice quality in order to be able to do it…

Last but not least, Korean makes an interesting distinction between “emphatic” (or fortis) obstruents and unaspirated and aspirated (lenis) obstruents.

What’s going on here? A variety of things occur during the articulation of fortis consonants in Korean. 1.Glottis is not open as wide (during closure) as in lenis stops.  Voicing begins more quickly after stop release 2.Increased airflow in fortis stops.  Higher F0 after stop release. 3.Vocal folds are “more tense” than in lenis stops. = greater medial compression = “squarer” glottal waveform

Why Should You Care? Remember that the most basic kind of sound wave is a sinewave. time pressure Sinewaves can be defined by three basic properties: Frequency, (peak) amplitude, phase

Complex Waves It is possible to combine more than one sinewave together into a complex wave. At any given time, each wave will have some amplitude value. A 1 (t 1 ) := Amplitude value of sinewave 1 at time 1 A 2 (t 1 ) := Amplitude value of sinewave 2 at time 1 The amplitude value of the complex wave is the sum of these values. A c (t 1 ) = A 1 (t 1 ) + A 2 (t 1 ) Note: a harmonic is simply a component sinewave of a complex wave.

Complex Wave Example Take waveform 1: high amplitude low frequency Add waveform 2: low amplitude high frequency The sum is this complex waveform: + =

Another Perspective Sinewaves can also be represented by their power spectra. Frequency on the x-axis Intensity on the y-axis (related to peak amplitude) WaveformPower Spectrum

Putting the two together WaveformPower Spectrum + + = = harmonics

More Combinations What happens if we keep adding more and more high frequency components to the sum? += +=

A Spectral Comparison WaveformPower Spectrum

What’s the Point? Remember our EGG waveforms for the different kinds of voice qualities: The glottal waveform for tense voice resembles a square wave.  lots of high frequency components (harmonics)

What’s the point, part 2 A modal voicing EGG looks like: It is less square and therefore has less high frequency components. Although it is far from sinusoidal...

What’s the point, part 3 Breathy and falsetto voice are more sinusoidal... And therefore the high frequency harmonics have less power, compared to the fundamental frequency.

Let’s Check ‘em out Head over to Praat and check out the power spectra of: a sinewave a square wave a sawtooth wave tense voice modal voice creaky voice breathy voice

Spectral Tilt Spectral tilt = drop-off in intensity of higher harmonics, compared to the intensity of the fundamental.