Speech Science II

1
Speech Science II

• Capturing and representing speech

2
Topics

• The empirical basis and the theoretical goal
• Capturing speech events
• Analysis and representation
• "Homework" a) Kent, Chap. 8, pp. 306-317
• b) Borden, Harris Raphael (3rd
  edition), Chap. 7, pp.234-260 Raphael,
  Borden Harris (5th edition), Chap. 12-13,
  pp.275-312
• Deutsch c) Pompino-Marschall, Teil I,
  S. 1-4
• Übung 2 (for 13 Nov) See Exercise sheet (hand
  in by 12 Nov).

3
The empirical basis

• Speech is open to controlled observation.
• It consists of registerable events. They can be
  repeated in a verifiable way.
• But, what is the nature of the observable events?
• Answer That depends on the domain you look at!

4
The goal

• Our goal is to explain how speech is produced and
  perceived (how we operate as speaking and
  listening individuals).
• I.e., to derive models of speech production and
  perception from quantitative analysis of speech
  processes (physical) in relation to the resulting
  speech events and their communicative function
  (experienced)
• Technically speaking, this is the relationship
  between the phenomenal and the
  trans-phenomenal
• If we only work in the physical domain, we have
  no link to what speech actually is and does
  namely something we experience, a phenomenon
• If we only work in the auditory domain, we cannot
  escape from the phenomenal (the subjective
  experience).

5
Two empirical domains?

• Speech was an area of empirical study long before
  the present-day instrumental methods were
  established.
• Linguists/Phoneticians wrote down what they
  heard
• Physiologists/Physicists registered
  articulatory/physical processes
• So which is preferable?
• The auditory observations are subjective
  and only record events that can be named
  (are linguistically defined)
• Instrumental records are objective and
  record selected aspects of the processes
  that took place during the speech event.

6
Interdependence (heard measured)
7
Levels of auditory analysis

• The limits to our auditory processing abilities
  has been nicely summarized by Tillmann (1980, p.
  39) The three prosodies
• The A-prosody is themelodic structure.
• The B-prosody is thesyllabic, rhythmicstructure.
  
• The C-prosody is thesegmental structure.
• We can only directlyexperience A and B.

8
Reality vs. analytic construct

• In our search for an explanation of how speech
  works, we work with observation to explain what
  we experience.
• The possible structure of what we experience as
  speech communication is an hypothesis (? theory)
  to be supported or falsified by interpretation of
  the observations.
• Most hypotheses are formulated as linguistic
  statements
• What are the sounds in the syllable, word ?
• What is the phonetic structure of the sound ?
• Is the syllable stressed, unstressed ?
• What are the tonal accents and where do they
  occur ?
• The reality of these analytic units is almost
  always taken for granted!

9
Capturing signals

• Each observation domain requires ist own method
  of capturing data.
• They differ greatly in the complexity, difficulty
  and expense
• Neural and neuro-physiological methods are VERY
  expensive,usually require medical supervision
  (or are only available ina medical research
  department).
• Physiological/articulatory methods are
  complicated and often rather expensive.
• Acoustic methods (and perceptual studies using
  acoustic stimuli)are relatively inexpensive and
  are readily available (nowadays)

10
Sub-glottal air-pressure analysis
Method 1 Balloon in the oesophagus
Disadvantages Indirect measurement, Position of
balloon critical(uncertain accuracy) Acceptabili
ty LOW!
11
Air-pressure analysis I
The air pressure in the balloon is thus
proportional to the sub-glottal pressure
12
Air-pressure analysis II
Method 2 Needle in the trachea!
Advantage Direct measurement
Disadvantage Medical supervision
necessary. Acceptability LOW!
13
Investigating glottal activity
1. Adduction and abduction Transglottal
illumination
14
Investigating glottal activity
2. Voicing Electroglottography (EGG)
15
Investigating articulation

• The accessibility of the articulator makes the
  problems of recording articulatory activity very
  specific
• Lips very accessible optical methods
  possible
• Jaw also accessible to optical or direct
  mechanical methods
• Tongue not directly accessible very complex
  movements
• Velum not accessible but relatively simple
  movements

16
Electropalatography
EPG registers the amount of contact between the
tongue and the palate. Advantage It captures
the changes of contact over time. Disadvantage
It only captures the Actual contact, not the
pressure, not the proximity to the palate. It
disturbs the articulation slightly.
17
(No Transcript)