Experimental studies of laryngeal articulation

135 Pages·2006·5.21 MB·English

by  Phil Hoole

Experimental studies of laryngeal
articulation
Philip Hoole
Part I: Electromyographic investigation of laryngeal activity in vowel
intrinsic pitch and consonant voicing

Experimental studies of laryngeal
articulation
Habilitationsschrift
zur Erlangung der Venia Legendi für das Fach Phonetik
Fakultät für Sprach- und Literaturwissenschaften
der Ludwig-Maximilians-Universität
vorgelegt von
Dr. phil. Philip Hoole
München, Oktober 2006
Part I: Electromyographic investigation of laryngeal activity in vowel
intrinsic pitch and consonant voicing

Preface
This study presents two sets of experiments on laryngeal function, entitled “Electromyographic
investigation of laryngeal activity in vowel intrinsic pitch and consonant voicing” (Part I), and
“Laryngeal-Oral Coordination in Consonant Sequences” (Part II)1.
Instrumental studies of articulatory processes are inevitably a collaborative endeavour, and it is
now a great pleasure to acknowledge all those involved in these experiments:
The EMG experiments grew out of a set of pilot experiments carried out at ATR Labs, Kyoto,
after I had approached Kiyoshi Honda with the idea of performing laryngeal EMG to find out
whether German really is a problem for theories of intrinsic pitch. I am very grateful to him for
the open ear he lent to my first tentative suggestions. However, it would never have been feasible
to carry out a full set of EMG recording sessions in Germany if I had been the only person
interested in this kind of data. The crucial elements, in addition to Kiyoshi Honda and Emi
Murano who did the needlework, were the interest and support of the phonetics lab of Zentrum
für Allgemeine Sprachwissenschaft, Berlin, together with the facilities of Rafael Laboissière’s
lab for sensorimotor coordination at the Max-Planck-Institute for Psychological Research,
Munich. This gave us the opportunity to record data relevant not just for the questions I was
originally interested in, but in particular also for lingual and mandibular function. Special
recognition is owed here to Christian Kroos who was the first subject for both laryngeal and
lingual EMG and thus boldly went - as far as I am aware - where no German subject had gone
before, at least in the context of hooked-wire EMG for phonetic research.
The second group of experiments, which used transillumination and fiberoptic filming to study
laryngeal kinematics, was carried out in Berlin at the ZAS phonetics lab, using an experimental
setup I had implemented some years ago. The specific topic of consonant sequences which is
focussed on here represents just one aspect of the many recordings we have carried out together
over the last few years. The long-suffering subjects for the present recordings were Ralf Winkler,
Suse Fuchs and Christian Geng (the latter two also gave freely of their neck and tongue for the
EMG experiments). Jörg Dreyer kept the lab running smoothly, and Dr. Klaus Dahlmeier wielded
a mean fiberscope.
Finally, this work is dedicated to Hans-G. Tillmann on the occasion of his retirement. His
unflagging enthusiasm for our subject over all the many years that he was head of phonetics at
Munich have been a tremendous motivation.
1Part II includes as an appendix the extended version of a very old conference paper
on velar and glottal activity in Icelandic. I prepared this extended version following the
conference but never published it. It seemed worth including here because the present
experiments in effect apply to German some ideas originally developed in that paper.
I - iv
Table of Contents for Part I
1 Introduction
.................................................... 1
2 Intrinsic Pitch in vowels: German as a test case
.......... 3
2.1 Introduction ................................................. 3
2.2 IF0. The basic issue: mechanics vs. active enhancement ....... 3
2.3 Tongue-pull theories ......................................... 5
2.4 Acoustic coupling ........................................... 7
2.5 EMG evidence for an active muscular contribution ............ 7
2.5.1 Honda & Fujimura (1991) ................................ 8
2.5.2 Autesserre et al. (1987) ................................... 9
2.5.3 Vilkman et al. (1989) ..................................... 9
2.5.4 Dyhr, 1990 .............................................. 9
2.5.5 Whalen et al., 1999 ...................................... 11
2.6 Vowel enhancement revisited ............................... 14
2.7 German as a test-case: The problem of tense vs. lax vowels ... 14
2.8 Is jaw position a relevant factor in IF0? ...................... 17
2.9 The necessity for EMG data on German ...................... 20
3 Cricothyroid activity and the relationship between F0 and
the control of consonant voicing
........................... 21
3.1 Introduction ................................................ 21
3.2 Voiceless consonants and raised F0: Early accounts .......... 22
3.2.1 Airflow hypothesis ...................................... 22
3.2.2 Vertical laryngeal tension hypothesis ...................... 23
3.2.3 Horizontal laryngeal tension hypothesis .................... 23
I - vi
3.3 A specific contribution of the cricothyroid: More recent evidence
............................................................ 23
3.3.1 Collier et al. (1979) ...................................... 23
3.3.2 Dixit & MacNeilage (1980) ............................... 24
3.3.3 Hutters (1985) .......................................... 26
3.3.4 Löfqvist et al. (1989) .................................... 28
3.4 A recent note on F0 and the perception of consonant voicing:
Whalen et al. (1993) ........................................ 30
3.5 Controlling the conditions under which vocal fold vibration can
occur: The contribution of vocal fold tension ................. 31
4 Experimental Procedures
.................................... 33
4.1 The principle of electromyography .......................... 33
4.2 EMG electrodes and insertion techniques .................... 34
4.2.1 Background to use of hooked-wire electrodes ................ 34
4.2.2 Electrode specifications for the current experiments .......... 36
4.3 Anatomical background ..................................... 36
4.4 Basic hardware setup for the present experiments ............. 38
4.5 Subjects: Insertions and speech material ..................... 38
4.5.1 Subject CK ............................................ 39
EMG insertions ......................................... 39
Speech Material ......................................... 39
4.5.2 Subject CG ............................................ 40
EMG insertions ......................................... 40
Speech Material ......................................... 40
4.5.3 Subject SF ............................................. 41
EMG insertions ......................................... 41
Speech Material ......................................... 41
Examples of artefacts ..................................... 42
4.6 Processing of the EMG data ................................. 44
4.6.1 Estimating strength of muscle activation .................... 44
4.6.2 Time alignment of EMG with F0 .......................... 47
4.6.3 Further pre-processing (1): Ensemble Averages ............. 49
4.6.4 Further pre-processing (2): Data reduction for statistical analysis
...................................................... 50
4.7 Acoustic processing: Calculation of fundamental frequency ... 50
I - vii
5 Results
......................................................... 51
5.1 Overview of the presentation of the results ................... 51
5.2 Tabulation of statistical results .............................. 52
5.3 Results for Consonant Voicing .............................. 55
5.3.1 EMG results ........................................... 55
Ensemble averages ...................................... 55
Statistical results for each segment .......................... 59
Summary of statistical results .............................. 62
5.3.2 F0 results .............................................. 63
Ensemble averages ...................................... 63
Statistical results for the vowel segment ...................... 66
5.3.3 Linking EMG and F0 ................................... 67
5.4 Results for the tense-lax opposition .......................... 69
5.4.1 EMG results ........................................... 69
Ensemble averages ...................................... 69
Statistical results for each segment .......................... 72
5.4.2 Relations between EMG and F0 ........................... 77
Ensemble averaged F0 .................................... 77
F0 vs. EMG: (1) Inspection of scatter plots of ensemble-averaged data
................................................ 82
F0 vs EMG: (2) Regression analysis of ensemble-averaged data ... 83
A diversion on consonant voicing ........................... 86
F0 vs. EMG (3): Alternative approach to regression analysis ..... 87
5.4.3 Discussion ............................................. 88
5.5 Vowel-specific EMG activity ................................ 89
5.5.1 The main effect of VOWEL .............................. 89
5.5.2 Basic F0 patterns in the vowels ............................ 89
5.5.3 Relationship between F0 and EMG: Overview ............... 90
5.5.4 Relationship between F0 and EMG: Regression analysis ...... 91
5.5.5 Discussion ............................................. 96
5.6 Functional differentiation of pars recta and obliqua of the
cricothyroid? ............................................... 97
5.6.1 Background ........................................... 97
5.6.2 Data .................................................. 98
I - viii
6 General Discussion
.......................................... 103
6.1 Tense vs. Lax .............................................. 103
6.1.1 Introduction .......................................... 103
6.1.2 Touching on perception ................................. 104
6.1.3 Final perspectives ...................................... 107
6.2 Vowel-specific effects ..................................... 108
6.3 Consonant voicing ......................................... 109
6.3.1 Introduction: The open questions ........................ 109
6.3.2 Two conflicting points of view and a possible third .......... 109
6.3.3 Consonantal articulation with vocalic effects: A shift of emphasis
..................................................... 112
6.3.4 Approaching a conclusion ............................... 116
6.3.5 Final conclusion: Sitting on the fence ..................... 117
6.4 The TENSE*VOICE interaction: A cautionary tale in experimental
design ..................................................... 118
7 References
.................................................... 119