SPPA 403 Speech Science1 Unit 3 outline The Vocal Tract (VT) Source-Filter Theory of Speech Production Capturing Speech Dynamics The Vowels The Diphthongs The Glides The Liquids

SPPA 403 Speech Science2 Articulation: Lecture Outline Brief anatomy review Introduction to Source-Filter Theory Introduction to tube acoustics

SPPA 403 Speech Science3 Supraglottal (Articulatory) system Comprised of –Cavities –Articulators

SPPA 403 Speech Science4 Supraglottal Cavities?

SPPA 403 Speech Science5 Oral Nasal Pharyngeal (Buccal)-cavity between the teeth and cheek Supraglottal Cavities

SPPA 403 Speech Science6 nasal cavity oral cavity pharyngeal cavity

SPPA 403 Speech Science7 The vocal tract

SPPA 403 Speech Science8 Immobile articulators?

SPPA 403 Speech Science9 Immobile articulators Hard palate Teeth

SPPA 403 Speech Science10 Hard Palate

SPPA 403 Speech Science11 Teeth

SPPA 403 Speech Science12 Mobile articulators?

SPPA 403 Speech Science13 Mobile articulators Pharyngeal walls Soft Palate Mandible Tongue Face, lips and cheeks

SPPA 403 Speech Science14 Pharyngeal walls

SPPA 403 Speech Science15 Soft palate

SPPA 403 Speech Science16 Mandible

SPPA 403 Speech Science17 Tongue

SPPA 403 Speech Science18 Face, lips and cheeks

SPPA 403 Speech Science19 The vocal tract

SPPA 403 Speech Science20 Unit 3 outline The Vocal Tract (VT) Source-Filter Theory of Speech Production Capturing Speech Dynamics The Vowels The Diphthongs The Glides The Liquids

SPPA 403 Speech Science21 Simplifying the vocal tract into “tubes” and “valves”

SPPA 403 Speech Science22 Simplifying the vocal tract into “tubes” and “valves”

SPPA 403 Speech Science23 The “tube” and “valve” analogy Tubes… –Act as an acoustic resonator or filter Valves… –Open and close the vocal tract to some tubes velopharyngeal port Oral articulator approximations –Serve as sound source Larynx (glottal spectrum) Within the vocal tract (i.e. /s/)

SPPA 403 Speech Science24 Source-filter theory of speech production The sounds we hear as speech is a function of –Sound source –Vocal tract filtering source and the filter are independent of each other

SPPA 403 Speech Science25 Source-filter theory simplified

SPPA 403 Speech Science26 Name that vowel! Same source, different filters

SPPA 403 Speech Science27 “Larynx? We don’t need no stinking larynx…”

SPPA 403 Speech Science28 Source characteristics The source –does not have to be the larynx –does not have to be periodic

SPPA 403 Speech Science29 Passing white noise through the filter

SPPA 403 Speech Science30 Passing white noise through the filter

SPPA 403 Speech Science31 Same source, different filters

SPPA 403 Speech Science32 Vocal tract as a tube

SPPA 403 Speech Science33 Vocal tract as a tube Tubes have physical characteristics Tubes are acoustic resonators Acoustic resonators have frequency response curves (FRC) Physical characteristics dictate FRC

SPPA 403 Speech Science34 Note Frequency response curve is also termed the transfer function

SPPA 403 Speech Science35 Frequency response curve (FRC) FRC peaks – resonant or formant frequency Resonators have an infinite number of formants F1, F2, F3 … denotes formants from low to high frequency F1F2F3F4

SPPA 403 Speech Science36 Vocal tract as a tube (Figure 9- 1) Vocal tract: bent tube, closed at one end, with differing Cross-sectional diameter. Straight tube, closed at one end, of differing cross-sectional diameter Straight tube, closed at one end, with a uniform cross-sectional diameter

SPPA 403 Speech Science37 Characteristics affecting filter properties Length. Cross-sectional area along its length. Whether it is closed at either or both ends.

SPPA 403 Speech Science38 Area function of a tube … Area (cm 2 ) Length along tube (cm)

SPPA 403 Speech Science39 Area function of a tube Area function dictates the frequency response curve for that tube Area (cm 2 ) Length along tube (cm)

SPPA 403 Speech Science40 Uniform tube (unchanging area function) closed at one end First resonance or formant F 1 = c/4l Where c=speed of sound (35,000 cm/sec) l = length of the tube

SPPA 403 Speech Science41 Uniform tube closed at one end Higher resonant frequencies or formants are odd multiples of F 1 For example, F 1 = (c/4l )*1 F 2 = (c/4l )*3 F 3 = (c/4l )*5

SPPA 403 Speech Science42 Tube example

SPPA 403 Speech Science43 What about the vocal tract? The vocal tract is fairly uniform in its cross- sectional diameter for neutral or central vowel (schwa)

SPPA 403 Speech Science44 Male vocal tract Average length 17.5 cm F 1 = (35000/4(17.5))*1 = 1*35000/70 = 500 Hz F 2 = (35000/4(17.5))*3 = 1500 Hz F 3 = (35000/4(17.5))*5 = 2500 Hz

SPPA 403 Speech Science45 Female vocal tract Average length 14 cm F 1 = (34000/4(14))*1 = 1*35000/56 = 607 Hz F 2 = (35000/4(14))*3 = 1821 Hz F 3 = (35000/4(14))*5 = 3035 Hz

SPPA 403 Speech Science46 Male-female comparison

SPPA 403 Speech Science47 Articulation in the context of source-filter theory neutral vocal tract configuration is an example of an articulatory configuration Articulation systematically changes –the filter properties of the vocal tract –the type of sound source