Phonetic details in prosodic phenomena

1
Phonetic details in prosodic phenomena

• Oliver Niebuhr
• Presentation at the Laboratoire de Phonétique et
  Phonologie, Paris 3
• January, 30th, 2009
• oliver.niebuhr_at_lpl-aix.fr

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Summary of German intonation (in terms of KIM)

• A number of attitudinal meanings are known to be
  signalled in German by prosodic means
• The speaker can convey that an information is
• (a) settled, concluding
• (b) presenting, open(ing)
• (c) astonishing
• Furthermore, speaker can
• (d) superordinate or
• (e) subordinate her/himself to the dialogue
  partner
• The specific interpretations of these attitudinal
  meanings may vary depending on the semantic
  composition and the linguistic structure of the
  utterance
• In negative contexts (a) may be interpreted as
  resignation and (c) as disbelieving / taken
  aback
• (d) and (e) can convey statement and question

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Summary of German intonation (in terms of KIM)

• In the Kiel Intonation Model (KIM, Kohler 1991),
  these attitudinal meanings have been assigned to
  pitch-accent categories
• The KIM distinguishes between 2 basic
  phonological classes of pitch movements
• rising-falling peaks
• G
• (falling)-rising valleys
• Co-occur with accented (i.e. perceptually
  salient) syllables
• Timing is phonological, not phonetic (?
  alignment) ? synchronization
• Relevant according to Kohler (1987, 1991) F0
  maximum (peaks) or minimum (valleys) relative to
  the accented-vowel boundaries (onsets)

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Summary of German intonation (in terms of KIM)

• early peaks ? F0 max. before acc.Von
  settled, concl.
• medial peaks ? F0 max. after acc.Von
  presenting
• late peaks ? F0 max. after acc.Voff
  astonishing
  
• early/late valleys ? F0 min. before/after
• acc.Von subordination /
• ? questioning

Did you hear me
Answer hmmnot exactly.
Answer yes, sure.
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The signalling of early, medial, and late peaks

• The reference to the accented-vowel boundaries in
  the KIM originates from peak-shift experiments by
  Kohler (1987, 1991).
• On the other hand, his experiments showed that
  the location of the category boundary is shifted
  for different stimulus utterances (Kohler 1991)
• Sie hat ja gelogen lateral vowel
• Sie ist ja geritten fricative vowel
• Sie hat ja gejodelt approximant vowel
• Why?

? earlier boundary
? later boundary
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The signalling of early, medial, and late peaks

• Niebuhr (2006, 2007c) maybe, it is not the
  segment boundary between CV in terms of a
  spectral change (e.g., formant transitions) that
  matters, but the increasing / decreasing
  intensity into and out of the accented vowel
• The intensity change is more abrupt for sequences
  nasalvowel or lateralvowel than for
  approximantvowel.
• It also depends on the vowel quality itself.
• Starting from this idea,
• Two f0 peak shift series were resynthesized
• One using the stimulus utterance Sie war mal
  Malerin
• The other hand keeps exactly the F0 and intensity
  patterns of the Malerin series, but on a
  constant Schwa-like vowel quality ( HUM in
  praat)
• So, basically, the two stimulus series (Malerin
  and HUM) differ just with regard to the
  presence / absence of the segmental string.
• Two parallel perception experiments with two
  separate groups of subjects
• Indirect identification for Malerin series
• AXB test for HUM series

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The signalling of early, medial, and late peaks
Indirect identification of inton. categories via
meaning
Context Stimulus
Test Stimuli
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The signalling of early, medial, and late peaks
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The signalling of early, medial, and late peaks
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The signalling of early, medial, and late peaks
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The signalling of early, medial, and late peaks
Malerin series

• The dynamics of the perceptual change from
  early to medial decreases with decreasing
  dynamics of the underlying intensity change.
• The same effect shows up, if a less pointed F0
  peak is shifted.
• A comparable effect of the dynamics of the F0 and
  intensity courses on the pitch-accent perception
  can be found for peak-shift series from medial
  to late, based on a manipulation of the
  decreasing intensity at the VC boundary

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The signalling of early, medial, and late peaks

• Conclusions of Niebuhr (2006, 2007c) The picture
  sketched by Kohler (1987, 1991) must be refined
• The abruptness of the perceptual changes between
  early, medial, and late is not determined
  by the categories themselves.
• The change from early to medial can be turned
  into a gradual one
• ? The change from medial to late can be made
  categorical
• The signalling of early, medial, and late
  is based on an interplay between F0 and intensity
  changes (or levels).
• ? The findings support the central claim of the
  KIM that the synchronization of the
  (rising-falling) F0-peak contour relative to the
  vowel boundaries is decisive for the pitch-accent
  identification
• The findings can explain to some extent, why
  different alignment patterns of the F0 peaks are
  found for different structures and segmental
  compositions of the accent syllable and the
  adjacent syllables. They also make sense in terms
  of articulatory anchoring.

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The signalling of early, medial, and late peaks
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The signalling of early, medial, and late peaks
mmm
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The signalling of early, medial, and late peaks

• ? Implication Synchronization itself is not
  phonological it is an effective, economic tool
  that speakers can use to highlight different
  parts of the pitch pattern by making use of the
  intensity pattern that results from the segmental
  string
• Alternative, complementary strategies changing
  the overall peak shape, changing intensity
  levels, changing segment durations and
  articulations (e.g., openness of the vowel,
  sibilant / intrinsic pitch)

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The signalling of early, medial, and late peaks

• Intonational difference in focus phrase-final
  (nuclear) high-rising valleys vs. terminal
  falling peaks
• Segments (Phonemes) in focus
• Phrase-final /?/
• Like /t/ aspiration, it can create sibilant
  pitch and is therefore particularly likely to
  vary systematically according to the peak-valley
  difference.
• Moreover /?/ is realized in German with rounding
  ?? this rounding does typically characterize
  already the preceding vowel ? e.g., Tisch
  t????.
• So, is /?/ in the context of a high-rising valley
  lighter than in the context of a terminal falling
  peak? Is rounding involved in this effect? If so,
  then the effect should already be noticeable in
  the vowel preceding /?/.

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The signalling of early, medial, and late peaks

• Intonational difference in focus phrase-final
  (nuclear) high-rising valleys vs. terminal
  falling peaks
• Segments (Phonemes) in focus
• Phrase-final /x/
• It is also able to convey pitch by means of
  changes in the energy pattern of the noise
  spectrum
• Moreover following /u/, /x/ is realized as a
  rounded velar fricative x?.
• So, is /x/ in the context of a high-rising valley
  lighter than in the context of a terminal falling
  peak? Is rounding involved in this effect? If so,
  then the effect should already be noticeable in
  the vowel /u/ preceding /x/.

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The signalling of early, medial, and late peaks

• Intonational difference in focus phrase-final
  (nuclear) high-rising valleys vs. terminal
  falling peaks
• Segments (Phonemes) in focus
• Phrase-final lt-ergt word endings
• It is realized as a vocoid sound ?, which is
  known to show considerable dialectal variation
  between ?? and ?
• So, is it also influenced by the coinciding
  intonation categories? If so, is it lighter (more
  fronted and/or open) in connection with
  high-rising valleys?
• Phrase-final /?/
• Its phonetic quality is known to be strongly
  context dependent in German
• So, is /?/ lighter (more fronted and/or open) in
  connection with high-rising valleys?

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The signalling of early, medial, and late peaks

• Pairs of target words (increases the n)
• Tisch, Fisch ? /?/ with preceding /?/
• Buch, Tuch ? /x/ with preceding /u/
• lecker, Bäcker ? lt-ergt realized as ?
• Tage, Schramme ? /?/
• Placed sentence- and hence phrase-finally in
  contexts of high-rising valleys and terminal
  falling peaks
• Acoustic analysis, including
• F2 (based on LPC LTAS) at three points in the
  vowels 20ms after onset, centre, 20ms before
  offset
• Centre-of-Gravity (CoG) determined every 7ms in
  the fricatives and then averaged across the whole
  fricative segment.
• Segment durations of vowels and fricatives

sibilant pitch
intrinsic vowel pitch
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The signalling of early, medial, and late peaks

• Corpus recorded with quasi-spontaneous, informal
  sounding speech, using an improved method of
  Kohler und Niebuhr (2007)
• This means
• Written dialogue texts with informal, everyday
  contents/situations.
• Target words are integrated sentence-finally
  without highlighting.
• The high-rising valleys and terminal falling
  peaks as well as the corresponding accented
  syllables are elicited solely by creating
  appropriate semantic-pragmatic contexts.
• Dialogues were produced by good friends.
• They were allowed to modify the texts according
  to their own way of speaking (e.g., by
  introducing or exchanging words and particles).
• One of the speakers was the experimenter (me) he
  tried to guide the subject with regard to
  speaking style, and his productions were part of
  the pragmatic context.
• Every dialogue was produced 4 times in a row, and
  only the last two productions were used for the
  acoustic analysis.
• So far, 5 subjects have been recorded (? n20),
  10 are planned.

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The signalling of early, medial, and late peaks

• Results for Tisch and Fisch
• The sibilant /?/ is considerably lighter in the
  contexts of the high-rising valley. This is
  reflected in significantly different mean CoG
  values. The fricative durations, however, do not
  differ significantly.
• Also the productions of /?/ differ depending on
  the intonation context. That is, F2 (middle) is
  significantly higher after the high-rising
  valley.
• Supported by perceptual analysis, this effect
  involves de-rounding.

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The signalling of early, medial, and late peaks

• Results for Buch and Tuch
• The fricative /x/ is considerably lighter in the
  contexts of the high-rising valley. This is
  reflected in significantly different mean CoG
  values. The fricative durations, however, do not
  differ significantly.
• Also the productions of /u/ differ slightly in
  the way that the F2 (middle) tends to be higher
  after the high-rising valley.
• Supported by perceptual analysis, this is again
  due to de-rounding.

peak
valley
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The signalling of early, medial, and late peaks

• Results for lecker and Bäcker
• The vocoid realizations of the word ending lt-ergt
  are not consistently lighter in connection with
  the high-rising valley. Such an effect i.e. a
  higher F2 can only be observed in tendency
  towards the end of the sound.
• ? in connection with the high-rising valley lt-ergt
  becomes a diphthongized ???, which also tends
  to be longer than in connection of the terminal
  falling peak.

peak
valley
650 1650
700 1300
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The signalling of early, medial, and late peaks

• Results for Tage and Schramme
• The productions of /?/ are lighter, i.e. they
  show a significantly higher F2 at the centre and
  towards the end of the vowel in connection with
  the high-rising valley.
• However, the vowel durations do not differ
  significantly depending on the intonational
  context.

peak
valley
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Summary of the intonational part

• We know that the F0 course contributes to the
  coding of segments
• F0 rise or fall before/after obstruents is a
  fortis-lenis cue (Kohler 1979)
• F0 relative to F1 determines the vowel quality
  (Traunmüller 1985)
• Position of F0 turning points cues word
  boundaries (DImperio 2000,Petrone 2008)
• (...)

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Summary of the intonational part
Intonation
Lexeme, Phoneme, Phone

• We need not forget that the segmental string is
  not (just) a troublemaker for the
• coding of intonational units
• The segmental contribution can the of two
  different kinds
• direct e.g., by intensity-based highlighting of
  parts of the F0 course, by conveying
• different sibilant or intrinsic (i.e.
  vowel-based) pitches
• indirect e.g., by articulatory metaphers of
  attitudinal meanings, i.e. long, soft, and
• light articulations for astonishment vs. short,
  loud, dark articulations for conclusions
• or superordinations, etc.

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Place assimilation in French sibilant sequences

• Based on a recent investigation of Niebuhr et al.
  (2008) within the S2S research network
• Starting from a corpus of read speech that
  comprised 72 sentences that may be subdivided
  into three subsets
• (1) the 8 possible sibilant sequences across word
  boundaries that result from the cross-combination
  of the features 'alveolar', 'postalveolar' and
  'voiced', 'voiceless', i.e. (a) /s?/, (b) /?s/,
  (c) /z?/, (d) /?z/, (e) /s?/, (f) /?s/, (g) /?z/,
  and (h) /z?/ ? placed in the symmetrical vowel
  contexts /i/___/i/, /a/___/a/, and /u/___/u/ (
  24).
• (2) (a) /s?/, (b) /?s/, (c) /z?/, (d) /?z/ framed
  by the 6 asymmetrical vowel contexts ( 24).
• (3) each of the 4 individual sibilants /s/, /?/,
  /z/, and /?/ paired across word boundaries with a
  labial consonant (C) like /p/ or /v/ in the two
  possible orders __C and C__ and framed by
  symmetrical vowel contexts ? reference qualities
  for the sibilants (24).
• All 72 sentences were read 4 times in a
  randomized order by 4 female native speakers of
  French

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Place assimilation in French sibilant sequences

• Based on a recent investigation of Niebuhr et al.
  (2008) within the S2S research network
• Starting from a corpus of read speech that
  comprised 72 sentences that may be subdivided
  into three subsets
• (1) /u?su/ Tu te couches sous l'drap
• (2) /as?a/ C'est une classe chargée
• (3) /uz?u/ J'ai vendu douze journaux
• (4) /az?a/ C'est une phrase japonaise
• (5) /a?Ca/ Tu te caches facilement
• (6) /izCi/ Il a une devise vitale
• (7) /aCsa/ Elle tape sa soeur

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Place assimilation in French sibilant sequences

• Measurements
• Spectral
• range and mean
• of the CoG across
• the whole section
• Duration
• of the whole section
• of the individual
• sibilants were
• possible

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Place assimilation in French sibilant sequences

• Results in the temporal domain
• If there were two spectrally separable sibilant
  sections, the postalveolar was always the longer
  one.
• Overall, the
• sequences
• were around
• twice as long
• as the single
• references,
• alv.-postalv.
• in tendency
• even more
• than
• postalv.-alv.

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Place assimilation in French sibilant sequences

• Results in the frequency domain
• The alveolar-postalveolar as well as the
  postalveolar-alveolar sequences were both
  spectrally
• shifted in a comparable
• way towards the
• postalveolar references.

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Place assimilation in French sibilant sequences

• Conclusions
• Place assimilation in French sibilant sequences
  is a gradual rather than a categorical phenomenon
• It is feature-determined, not direction-determined
  . The target is postalveolar. Consequently, it is
  regressive in alveolar-postalveolar and
  progressive in postalveolar-alveolar sequences.
• ? Elle remâche sa viande /?s/ ? ?
• ? Cest une classe chargée /s?/ ? ?
• The assimilated alveolar-postalveolar and
  postalveolar-alveolar sequences can have
  phonetically identical manifestations in terms of
  both temporal and spectral values.
• But are these sequences really ambiguous?

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Place assimilation in French sibilant sequences

• Nolan (1992) found for English that word-final
  /d/s which were completely assimilated to
  following word-initial /g/s (in terms of EPG
  patterns) were still identified as /d/s by his
  subjects.
• He ascribed this effect to differences in the
  preceding vowel.
• Starting from this interesting observation, which
  was not further pursued so far, we investigated
  whether the vowels that preceded the assimilated
  /s?/ and /?s/ sibilant sequences in French show
  differences in phonetic details that can be used
  by listeners to identify the even those following
  sibilant sequences as /s?/ or /?s/ that are
  ambiguously realized as ?.

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Place assimilation in French sibilant sequences

• This is what we found for vowel duration and
  vowel intensity
• The vowels /a, i, u/ were significantly longer
  when they preceded /?s/ (on average 15-20ms, up
  to 60ms).
• The vowels /a, i, u/ were significantly louder
  when they preceded /s?/ (on average 2-3dB, up to
  5dB).

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Place assimilation in French sibilant sequences

• And in addition we found for voice quality
• The vowels /a, i, u/ were significantly breathier
  when preceded by /?s/.
• The voice quality was represented by the harmonic
  ratios H1/H2, based on narrow band DFT spectral
  at three points in the vowel 20ms after onset,
  centre, 20ms before offset.
• On the other hand, the vowels before /s?/
  sometimes show a short section of /h/-like
  friction before the actual sibilant sets in (
  different timing of breath?)

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Place assimilation in French sibilant sequences
/s?/
/?s/
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Place assimilation in French sibilant sequences
/s?/
/?s/
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Summary of the assimilation part

• Initial perceptual tests were done in which (a)
  just the CV part of the first target syllable and
  (b) just the sibilant section itself was played
  to non-naïve native speakers of French. The
  preliminary results show that the listeners were
  only able for (a) to predict beyond change level
  whether the upcoming sibilant sequence was /s?/
  or /s?/.
• So, the multi-parametric phonetic details in the
  vowels preceding the sibilant sequences might
  already be acoustic cues to the phonological
  make-up of the sibilant sequence, even if the
  phonetic realization of the latter is by itself
  ambiguous.
• This suggests that the term gradual has a
  temporal implication beyond the sibilant sequence
  itself.
• Moreover, the fine phonetic differences in the
  vowels were not found in the same way before
  single, non-assimilated sibilant. This might be
  taken as evidence that place assimilation within
  French sibilant sequences represents a
  re-organization rather than a (gradual)
  substitution of phonological features, in line
  with previous findings of many other assimilation
  processes across languages.