Module 3 Flashcards
How do sounds originate? What determines the nature of a sound?
Movement! Oscillation of vocal folds. Movement characteristics.
What is many degrees of freedom?
Many different elements that can be individually adjusted to change speech.
How is acoustic analysis noninvasive?
We draw inferences about movements from sound.
Disordered voice= disordered vocal fold movement SOURCE change
Disordered articulation a= abnormal movement of the articulators FILTER change
What are some limitations of acoustic analysis? What is motor equivalence?
Acoustic patterns reflect vocal tract movements with some ambiguity. Motor equivalence is the same sound can be produced several ways! Can’t reveal ALL details of movement.
What are the filter types?
High pass- allows high frequencies, holds back lowers
Low pass- allows low frequencies through, holds back higher ones
Band pass- remove high and low, allows band in the middle to pass through more easily
Band reject- holds back a band of frequencies, allows rest through
If you alter proportions of a sound, you alter…
Quality!
Fourier theorem?
All periodic sounds are made of a combination of sine waves- but amplitudes, phase angles, frequencies vary
What is a Fourier transform?
Creates a spectrum from the time domain waveform- analyze to learn “ingredients”
What does a waveform represent on a time domain?
Sound directly, air pressure changes over time!
What does a frequency domain show? What’s it greatest benefits?
Line spectrum shows the frequency components of a periodic sound. The proportions of the frequencies
Why is the human voice nearly periodic?
Has a fundamental and harmonics above it. Harmonics weaker as up in frequency
Harmonics come together as pitch goes …, apart when pitch goes…
Down, up
What does a sine wave look like? Complex periodic signals? Noise?
Sine wave is a single line on a spectrum
Complex periodic signals is multiple lines
Noise is all frequencies equal amplitude random phase
What is a spectral envelope?
Encloses an area that would have been filled in by lines. Shows tops of where all lines would be which shows strengths of different components in frequency
Is the voice source periodic?
No nearly. Spectrum does not have pure lines, has peaks. Spread of energy around fundamental and harmonics.
