19 - Basic Issues in Speech Perception Flashcards
Name 2 of the 4 basic issues in speech perception
Linearity problem
Segmentation problem
Acoustic-perceptual (invariance) problem
Unit of speech
If speech perception/production were truly linear, what would we see?
Each perceived phoneme in an utterance would be a discrete and non-overlapping stretch of sound
-instead we see overlapping features
What is the segmentation problem with speech perception?
The physical temporal boundaries between phonemes are often difficult to define on the acoustic signal
What is the acoustic-perceptual invariance problem?
The invariant units of perception (ie. phonemes) do not correspond to invariant acoustic signals
-acoustic features for a given phoneme can show a great deal of variation as a function of phonetic context
What problem has caused a number of speech scientists to reject the phoneme as the basic unit of speech?
The context sensitivity problem
Name 2 possible units of analysis for speech perception
Phonetic features
Phonemes
Syllables
Morphemes
What is the name of the Theory that combines morphemes, syllables, phonemes, and features into one model of unit of speech perception?
Dell’s Spreading Activation Theory
What are the 2 methods in speech perception?
Preparation of stimuli
Presentation of stimuli
Describe the pattern playback device and state which method is speech perception it belongs to
Preparation of stimuli
- painted formant patterns on acetate film loops, which were converted into acoustic signals by a photoelectric system
What are 2 of the 4 “preparation of stimuli” techniques?
Pattern playback device
Waveform editing and filtering
Formant synthesizer
LPC resynthesis (Linear Predictive Coding)
The method of speech perception that involves temporal manipulations of speech, and adding or removing selected segments is called what?
Waveform editing and filtering
If we speak 2 times faster, how fast will we perceive it to be?
6 times faster
What does autophonic mean?
Perception of a change in our own speech rate
What does extraphonic refer to?
Perception of a change in the speech rate of others
When we hear someone else produce a rate of speech that is 2 times faster, how fast do we perceive it to be?
3 times faster
How can we use frequency filtering to demonstrate the importance of frequency in perception?
Use Praat to remove lower frequencies of “sh” to get “s”
What was one of the predominant synthesizers of the 60’s and 70’s that was used by Stephen Hawking?
The Klatt synthesizer (DEC talk)
What does the Klatt synthesizer allow you to do?
Selectively manipulate over 40 different parameters
Name 2 parameters that the Klatt synthesizer could manipulate
Klatt is a formant-based text-to-speech synthesizer, so:
F0 Formant freq Formant amplitude Formant bandwidth Noise frequency Noise amplitude
- artificial sounding
- wide range of voice adjustments
- works well at rapid rates (+300 wpm)
What is Acapela?
A sample-based text-to-speech engine
- very natural sounding
- limited voice types or adjustments
- may not work well at rapid rates
What does LPC stand for?
Linear Predictive Coding
-computer uses natural speech, performs LPC analysis, then provides a list of variables that can be selectively manipulated
What are 2 of the 3 Presentation of Stimuli procedures?
Discrimination procedures
Rating procedures
Identification procedures
True or False: Discrimination tasks use forced choice to determine what parameters play a role in speech perception
True
Which Presentation of Stimuli procedure involves equal appearing interval scales and visual analogue scales?
Rating procedures
