Oliver Niebuhr

The Signalling of German Rising-Falling Intonation Categories – The Interplay of Synchronization, Shape, and Height

Based on the phonology of the Kiel Intonation Model (KIM), a tripartite opposition of German intonation is investigated: early, medial, and late peaks. These intonation categories, which can be projected onto H + L*, H*, and L* + H in the AM framework, are described in the KIM as rising-falling F0 peak patterns differentiated by their synchronization with the accented-vowel onset. Perception experiments were carried out, showing that the function-based identification of the peak categories is not only influenced by peak synchronization, but also by peak shape and height. While the complete spectrum of findings is not covered by the current phonological modelling, the findings corroborate the existence of all three categories in German intonation and support the idea that the timing of the peak movements with regard to the accented vowel is important for their perceptual differentiation.

On the Phonetics of Intensifying Emphasis in German

This paper presents an exploratory study in the field of emphasis in German. It provides a comprehensive acoustic analysis for a type of emphasis that intensifies lexical meanings either positively or negatively. A speech corpus was recorded using an elicitation method adapted to yield natural-sounding, conversational, expressive speech under controlled conditions. Supporting the distinction between positive and negative intensification, two clearly different phonetic profiles emerged. These phonetic profiles of positive and negative intensification involve voice quality as well as the dynamics of the speech signal across its segmental and prosodic layers. By means of these profiles, the intensifying emphases were correctly classified by a discriminant analysis as positive or negative in around 90% of the cases. Moreover, indications were found for a third type of intensifying emphasis, which was called ‘reinforcement’. Its multidimensional phonetic profile falls in between the ones of positive and negative intensification.

F₀-Based Rhythm Effects on the Perception of Local Syllable Prominence

A perception experiment shows for German that different global, F₀-based speech rhythms in the context section of stimuli influence the local prominence position in the target section. This effect may be conceptualized as a perceptual adjustment of the syllables in the target section to the ones of the global rhythmic context with regard to both the prominence and the F₀ patterns. Two conclusions were drawn on this basis. First, listeners use speech rhythm to predict the perceptual properties of syllables, which is in line with the guide function that speech rhythm is assumed to have in German and other Western Germanic languages. Secondly, speech rhythm is a perceptual phenomenon, generated by a cyclic construction process that involves repetitive patterns in multiple dimensions. Thus, although speech rhythm is initiated by changes in acoustic parameters, it cannot be soaked up by acoustic measurements, especially, if these measurements refer to duration alone.

On the intonation of German intonation questions: the role of the prenuclear region.

German questions and statements are distinguished not only by lexical and syntactic but also by intonational means. This study revisits, for Northern Standard German, how questions are signalled intonationally in utterances that have neither lexical nor syntactic cues. Starting from natural productions of such ‘intonation questions’, two perception experiments were run. Experiment I is based on a gating paradigm, which was applied to naturally produced questions and statements. Experiment II includes two indirect-identification tasks. Resynthesized stimuli were judged in relation to two context utterances, each of which was compatible with only one sentence mode interpretation. Results show that utterances with a finally falling nuclear pitch-accent contour can also trigger question perception. An utterance-final rise is not mandatory. Also, question and statement cues are not restricted to the intonational nucleus. Rather, listeners can refer to shape, slope, and alignment differences of the preceding prenuclear pitch accent to identify sentence mode. These findings are in line with studies suggesting that the utterance-final rise versus fall contrast is not directly related to sentence modality, but represents a separate attitudinal meaning dimension. Moreover, the findings support that both prenuclear and nuclear fundamental frequency (F0) patterns must be taken into account in the analysis of tune meaning.

On place assimilation in sibilant sequences: Comparing French and English

Abstract Two parallel acoustic analyses were performed for French and English sibilant sequences, based on comparably structured read-speech corpora. They comprised all sequences of voiced and voiceless alveolar and postalveolar sibilants that can occur across word boundaries in the two languages, as well as the individual alveolar and postalveolar sibilants, combined with preceding or following labial consonants across word boundaries. The individual sibilants provide references in order to determine type and degree of place assimilation in the sequences. Based on duration and centre-of-gravity measurements that were taken for each sibilant and sibilant sequence, we found clear evidence for place assimilation not only for English, but also for French. In both languages the assimilation manifested itself gradually in the time as well as in the frequency domain. However, while in English assimilation occurred strictly regressively and primarily towards postalveolar, French assimilation was solely towards postalveolar, but in both regressive and progressive directions. Apart from these basic differences, the degree of assimilation in French and English was independent of simultaneous voice assimilation but varied considerably between the individual speakers. Overall, the context-dependent and speaker-specific assimilation patterns match well with previous findings.

Perception of phonetic detail in the identification of highly reduced words

Abstract There is great phonetic variation of words in context, conditioned by phonetic environment, word type, and speaking style in different communicative situations. Function words and modal particles are particularly susceptible to having their phonetic weight and complexity reduced, especially in casual spontaneous speech. But even if whole strings of segments are no longer delimitable in reduced forms compared with fuller pronunciations of the same lexical items, there will still be articulatory prosodies, superimposed upon the remaining sound material, which retain essential components of the fuller forms, the phonetic essence that characterizes the whole form class of a word. The extreme reduction [a ɪ ˜ i ˜ ] of the German modal particle eigentlich ‘actually’ [aɪ(ɡ)ŋ.(t)(l)i(c)] is a case in point. The length, palatality and nasality of its gliding movement reflect the polysyllabicity, the central nasal consonant and the final palatal syllable of the fuller forms. It is assumed that this phonetic essence triggers lexical identification in the listener. Therefore two perceptual identification experiments were carried out. They showed the crucial role of the duration of a palatal gliding section in the diphthong [a ɪ ˜ i ˜ ] to distinguish between eine__ ‘one__’ and eigentlich’ne__ ‘actually a__’. A third test showed further that listeners reacted differently to the palatal glide duration in different reduction environments, which may be related to different functional assessment of reduced forms in situational contexts.

At the edge of intonation: the interplay of utterance-final F0 movements and voiceless fricative sounds.

The paper is concerned with the ‘edge of intonation’ in a twofold sense. It focuses on utterance-final F0 movements and crosses the traditional segment-prosody divide by investigating the interplay of F0 and voiceless fricatives in speech production. An experiment was performed for German with four types of voiceless fricatives: /f/, /s/, /ʃ/ and /x/. They were elicited with scripted dialogues in the contexts of terminal falling statement and high rising question intonations. Acoustic analyses show that fricatives concluding the high rising question intonations had higher mean centres of gravity (CoGs), larger CoG ranges and higher noise energy levels than fricatives concluding the terminal falling statement intonations. The different spectral-energy patterns are suitable to induce percepts of a high ‘aperiodic pitch’ at the end of the questions and of a low ‘aperiodic pitch’ at the end of the statements. The results are discussed with regard to the possible existence of ‘segmental intonation’ and its implication for F0 truncation and the segment-prosody dichotomy, in which segments are the alleged troublemakers for the production and perception of intonation.

Acoustic Patterns and Communicative Functions of Phrase-Final F0 Rises in German: Activating and Restricting Contours

Acoustic features and communicative functions of phrase-final F0 rises startingbefore an accented-vowel onset are analysed in a corpus of German unscriptedspeech. Two conversational conditions are examined: turn-yielding and turn-holding.The most important feature distinguishing rises in these two conditions is therange proportion, which differentiates between two patterns as follows: (1) raisedpitch on the accented syllable and restrained pitch movement in the tail of thecontour, (2) lowered pitch on the accented syllable and extended pitch movementin the tail. The first pattern is seen as a restrictivegesture, e.g. preventing the dia-loguepartner from turn taking. The second one is viewed as an activatinggesture,inviting the coparticipant to contribute.

On the role of articulatory prosodies in German message decoding.

A theoretical framework for speech reduction is outlined in which ‘coarticulation’ and ‘articulatory control’ operate on sequences of ‘opening-closing gestures’ in linguistic and communicative settings, leading to suprasegmental properties – ‘articulatory prosodies’ – in the acoustic output. In linking this gestalt perspective in speech production to the role of phonetic detail in speech understanding, this paper reports on perception experiments that test listeners’ reactions to varying extension of an ‘articulatory prosody of palatality’ in message identification. The point of departure for the experimental design was the German utterance ich kann Ihnen das ja mal sagen ‘I can mention this to you’ from the Kiel Corpus of Spontaneous Speech, which contains the palatalized stretch [k̟hε̈njnjəs] for the sequence of function words /kan i.n(ə)n das/ kann Ihnen das. The utterance also makes sense without the personal pronoun Ihnen. Systematic experimental variation has shown that the extent of palatality has a highly significant influence on the decoding of Ihnen and that the effect of nasal consonant duration depends on the extension of palatality. These results are discussed in a plea to base future speech perception research on a paradigm that makes the traditional segment–prosody divide more permeable, and moves away from the generally practised phoneme orientation.

The Phonetic Manifestation of French /s#∫/ and /∫#s/ Sequences in Different Vowel Contexts: On the Occurrence and the Domain of Sibilant Assimilation

While assimilation was initially regarded as a categorical replacement of phonemes or phonological features, subsequent detailed phonetic analyses showed that assimilation actually generates a wide spectrum of intermediate forms in terms of speech timing and spectrum. However, the focus of these analyses predominantly remained on the assimilated speech sound. In the present study we go one step ahead in two ways. First, we look at acoustic phonetic detail that differs in the French vowels /i, a, u/ preceding single /s/ and /∫/ sibilants as well as /s#∫/ and /∫#s/ sibilant sequences. Second, our vowel measurements include not only F1 and F2 frequencies, but also traditional prosodic parameters like duration, intensity and voice quality. The vowels and sibilants were recorded as the central part of CVC#CVC pseudo-names in a contextualized read-speech paradigm. In the single-sibilant conditions we found that the vowels preceding /∫/ were longer, breathier, less intense, and had more cardinal F2 values than before /s/. For the /s#∫/ and /∫#s/ conditions we found regressive and progressive /s/-to-[∫] assimilation that was complete in terms of spectral centre-of-gravity measurements, although French is said to have only voice assimilation. Moreover, the vowels preceding the /s#∫/ sequences still bear an imprint of /s/ despite the assimilation towards [ ∫∫]. We discuss the implications of these findings for the time window and the completeness of assimilation as well as for the basic units in speech communication.