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Paper presented at FONETIK 2019, 10-12 June 2019, Stockholm

International audience

This paper evaluates articulation rate measures and rate characteristics of read and spontaneous speech on the basis of a manually labelled database for German. The results of phone classification experiments for three different articulation rates only partially confirm our expectations. Phonetic explanations are suggested.

This study focuses on the implementation of the phonetic effects of vowel accentuation in automatic speech recognition (ASR). The durational and spectral effects of accentuation are investigated separately by manipulating the transition and observation probabilities in hidden Markov models. We also attempt to implement the undershoot hypothesis [1], which describes spectral reduction as a direct consequence of shortening. Our findings support the widespread belief that the transition probabilities, which indirectly model durational effects, are negligible, and that the distinction between accented and unaccented vowels is determined by the observation probabilities.

Breathing is fundamental for living and speech, and it has been a subject of linguistic research for years. Recently, there has been a renewed interest in tackling the question of possible communicative functions of breathing (e.g. Rochet-Capellan & Fuchs, 2014; Aare, Włodarczak & Heldner, 2014; Włodarczak & Heldner, 2015; Włodarczak, Heldner, & Edlund, 2015). The present study set out to determine acoustic markedness and communicative functions of pauses accompanied and non-accompanied by breathing. We hypothesised that an articulatory reset occurring in breathing pauses and an articulatory freeze in non-breathing pauses differentiates between the two types. A production experiment was conducted and some evidence in favour of such a phenomenon was found. Namely, in case of non-breathing pauses, we observed more coarticulation evidenced by a more frequent omission of plosive releases. Our findings thus give some evidence in favour of the communicative function of breathing.

Sammendrag Denne oppgaven prøver å finne svar på om fysisk oppvarming har betydning for stemmekvaliteten sett på stemmebåndsnivå. 21 amatørsangere gjennomgikk tre oppvarmingsprogram; fysisk oppvarming, stemme-oppvarming og kombinert oppvarming, med lydopptak av en lest tekst og en utholdt vokal før og etter. Akustisk analyse ble brukt for å undersøke regularitet og kvalitet i stemmebåndssvingningene, målt med HNR og perturbasjons-målene jitter og shimmer. Deltakernes grunnfrekvens og intonasjons-målet SD pitch ble også målt i teksten for å finne ut om oppvarmingene hadde effekt på disse parametrene. Det ble undesøkt om deltakerne opplevde effekt av oppvamingene, og resultatene ble sammenlignet med de akustiske analysene for å se om det var sammenheng mellom målt effekt og deltakernes opplevde effekt. Et lite persepsjoneksperiment undersøkte til slutt om forskjellen på stemmekvaliteten kunne høres for et trent øre. I følge teori om trening skal oppvarming øke muskeltemperaturen, noe som gir fordeler som økt oksygenopptak, økt utskillelse av avfallsstoffer og mykere og mer fleksible muskler som tåler større belastning. Økt evne til avspenning, bedre flyt i pusten, endret viskositeten i muskler, bedre nevral kontroll, bedre energibalansen i kroppen og økt kroppsbevissthet er andre effekter som tillegges fysisk oppvarming. Spesiell oppvarming, som går direkte på aktiviteten som skal utføres, skal gi en ekstra effekt, særlig pga. økt nevral aktivering. I lys av dette forventes størst effekten av kombinert oppvarming der man nyter godt av både fordelene ved økning i muskeltemperatur og de ergogene fordelen ved spesiell oppvarming. Analysene viste få signifikante forskjeller mellom oppvarmingsprogrammene, men i resultatene for tekstene hadde alle de tre oppvarmingen gjennomsnittlig positiv effekt på stemmekvaliteten sammenlignet med ingen oppvarming. Effekten var todelt: kombinert oppvarming hadde størst effekt på pitch-målene, mens stemmeoppvarming hadde størst effekt på stemmekvalitetsmålene unntatt shimmer der kombinert oppvarming viste best effekt. På den utholdte vokalen hadde fysisk oppvarming alene gjennomsnittlig negativ effekt på jitter og HNR. Stemmeoppvarming hadde gjennomsnittlig best effekt på jitter og HNR, mens shimmer hadde størst forbedring etter kombinert oppvarming. Shimmer og HNR-verdiene var imidertid aller best etter ingen 2, altså uten oppvarming. Pitch og SD pitch gikk signifikant opp etter alle typer oppvarming, og mest etter kombinert oppvarming. Stemmekvalitetsmålene hadde størst forbedring ved høyere pitch. Deltakerne opplevde positiv effekt av oppvarmingene, og mest etter kombinert opp-varming. Det ble ikke funnet noen signifikante sammenhenger mellom opplevd effekt og målt effekt på stemmekvalitet. De perseptuelle analysene viste noen få signifikante sammenhenger mellom vurderingene til 5 ulike lyttere, men vurderingene korrespon-derte lite med type oppvarming og målt stemmekvalitet. Resultatene fra undersøkelsen viser at oppvarming kan ha en effekt på stemmekvaliteten målt på stemmebåndsnivå, men effekten er individuell og kan være både positiv og negativ. Personlig tilpasning er derfor viktig. Stigning av f0 i talestemmen etter opp-varming kan gi en liten risiko for overbelastning og bør tas med i vurderingen i behandling av f.eks. stemmetretthet. Abstract The purpose of this study was to determine if aerobe warm-up has an impact on voice quality as it is measured in acoustic analysis. 21 amateur singers completed three different warm-up strategies: aerobe warm-up, vocal warm-up and combined warm-up, with recording of a read text and a sustained vowel before and after warm-up. Acoustic analysis was used to examine regularity and quality of the vocal fold vibrations, measured by HNR, jitter and shimmer. Fundamental frequency and the standard deviation of fundamental frequency was measured as well to determine if warm-up had an influence on these measurements. The participants self-perceived effect was collected and compared with the measured effects from the acoustic analysis to see if they corresponded. At last, a small perception experiment was completed to investigate if trained vocal pedagogues and -therapists can hear these changes in voice quality. According to theory of training aerobe warm-up increases blood flow and muscle temperature, which results in improved oxygen delivery and use, facilitated muscle metabolism and decreased stiffness of muscle and joints. Aerobe warm-up can also result in faster muscle contractions and relaxation, better airflow, greater economy of movements because of lowered viscous resistance within active muscles, increased transmission rate of nerve impulses, better energy balance of the body and better body awareness. Task-specific warm-up is claimed to give additional benefits possibly by increasing neuromuscular activation. According to this, a combined warm-up is expected to have greatest effect on voice quality, because of the benefits of both increased muscle temperature and the ergogenic benefits of task-specific warm-up. Few significant differences were found comparing the three warm-up protocols. However, the analysis of the texts showed average positive effects on voice quality compared to no warm-up. The effect was divided: combined warm-up showed the greatest effect on pitch-measurements, and the vocal warm-up on the voice-quality measures jitter and HNR. The results for shimmer were best after combined warm-up. For the sustained vowel physical warm-up alone had a negative impact on jitter and HNR. Vocal warm-up had the average best effect on jitter and HNR, while shimmer had the greatest improve-ment after combined warm-up. However, the values of shimmer and HNR was best after no warm-up 2. Pitch and SD pitch increased significantly after all warm-ups, but most after combined warm-up. The voice-quality measures increased the most by higher pitch. The participants experienced positive effects from all warm-ups, but most after combined warm-up. No significant correlations were found between reported effects and measured effects in the acoustic analysis. A few significant correlations between the listeners assessments of voice quality were found in the perceptual analysis, although the assessments had low correlations with type of warm-up and measured voice quality. The results in this study shows that warm-up can have an effect on voice quality measured on a vocal cord level, but the effect is individual and can be both positive and negative. This implies that it is important to customize the activity to each individual. The increased fundamental pitch of the speaking voice can constitute a risk of vocal loading and must be considered in intervention of different voice problems as for instance muscle tension disorder.