19 - Basic Issues in Speech Perception

Question 1

Name 2 of the 4 basic issues in speech perception

Answer 1

Linearity problem
Segmentation problem
Acoustic-perceptual (invariance) problem
Unit of speech

Question 2

If speech perception/production were truly linear, what would we see?

Answer 2

Each perceived phoneme in an utterance would be a discrete and non-overlapping stretch of sound

-instead we see overlapping features

Question 3

What is the segmentation problem with speech perception?

Answer 3

The physical temporal boundaries between phonemes are often difficult to define on the acoustic signal

Question 4

What is the acoustic-perceptual invariance problem?

Answer 4

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

Question 5

What problem has caused a number of speech scientists to reject the phoneme as the basic unit of speech?

Answer 5

The context sensitivity problem

Question 6

Name 2 possible units of analysis for speech perception

Answer 6

Phonetic features
Phonemes
Syllables
Morphemes

Question 7

What is the name of the Theory that combines morphemes, syllables, phonemes, and features into one model of unit of speech perception?

Answer 7

Dell’s Spreading Activation Theory

Question 8

What are the 2 methods in speech perception?

Answer 8

Preparation of stimuli

Presentation of stimuli

Question 9

Describe the pattern playback device and state which method is speech perception it belongs to

Answer 9

Preparation of stimuli

• painted formant patterns on acetate film loops, which were converted into acoustic signals by a photoelectric system

Question 10

What are 2 of the 4 “preparation of stimuli” techniques?

Answer 10

Pattern playback device
Waveform editing and filtering
Formant synthesizer
LPC resynthesis (Linear Predictive Coding)

Question 11

The method of speech perception that involves temporal manipulations of speech, and adding or removing selected segments is called what?

Answer 11

Waveform editing and filtering

Question 12

If we speak 2 times faster, how fast will we perceive it to be?

Answer 12

6 times faster

Question 13

What does autophonic mean?

Answer 13

Perception of a change in our own speech rate

Question 14

What does extraphonic refer to?

Answer 14

Perception of a change in the speech rate of others

Question 15

When we hear someone else produce a rate of speech that is 2 times faster, how fast do we perceive it to be?

Answer 15

3 times faster

Question 16

How can we use frequency filtering to demonstrate the importance of frequency in perception?

Answer 16

Use Praat to remove lower frequencies of “sh” to get “s”

Question 17

What was one of the predominant synthesizers of the 60’s and 70’s that was used by Stephen Hawking?

Answer 17

The Klatt synthesizer (DEC talk)

Question 18

What does the Klatt synthesizer allow you to do?

Answer 18

Selectively manipulate over 40 different parameters

Question 19

Name 2 parameters that the Klatt synthesizer could manipulate

Answer 19

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)

Question 20

What is Acapela?

Answer 20

A sample-based text-to-speech engine

• very natural sounding
• limited voice types or adjustments
• may not work well at rapid rates

Question 21

What does LPC stand for?

Answer 21

Linear Predictive Coding
-computer uses natural speech, performs LPC analysis, then provides a list of variables that can be selectively manipulated

Question 22

What are 2 of the 3 Presentation of Stimuli procedures?

Answer 22

Discrimination procedures
Rating procedures
Identification procedures

Question 23

True or False: Discrimination tasks use forced choice to determine what parameters play a role in speech perception

Answer 23

True

Question 24

Which Presentation of Stimuli procedure involves equal appearing interval scales and visual analogue scales?

Answer 24

Rating procedures

Question 25

An intelligibility test would be an example of what type of presentation of stimuli procedure?

Answer 25

Identification Procedures

Question 26

What is an example of an identification procedure for the presentation of stimuli?

Answer 26

Intelligibility tests, such as Speech in Noise tests and the Sentence Intelligibility Test (SIT)

Question 27

The sentence intelligibility test can be conducted using sentences or ___

Answer 27

Single words

Question 28

What is the purpose of the phonetic intelligibility test?

Answer 28

To attempt to provide a phonetic explanation for the patient’s intelligibility deficit
-examines 19 phonetic errors that commonly occur in dysarthria

Question 29

What is the McGurk Effect?

Answer 29

How the visual presentation of speech can interfere with our auditory perception of speech

Question 30

True or False: We know for sure that speech perception is special

Answer 30

No; this is still up for debate

• one side says we just use general principles of auditory perception
• other says it is special

Question 31

How do the “special” vs “non-special” arguments for speech perception relate to adult categorical perception?

Answer 31

Adult categorical perception

• abrupt shift in /b/, /d/, and /g/ thought to be evidence of special mechanisms
• non-speech stimuli show evidence of categorical perception??