This study explores the influence of lexicality on gradient judgments of Swedish sibilant fricatives by contrasting ratings of initial fricatives in words and word fragments (initial CV-syllables). Visual-Analogue Scale (VAS) judgments were elicited from experienced listeners (speech-language pathologists; SLPs) and inexperienced listeners, and compared with respect to the effects of lexicality using Bayesian mixed-effects beta regression. Overall, SLPs had higher intra- and interrater reliability than inexperienced listeners. SLPs as a group also rated fricatives as more target-like, with higher precision, than did inexperienced listeners. An effect of lexicality was observed for all individual listeners, though the magnitude of the effect varied. Although SLP’s ratings of Swedish children’s initial voiceless fricatives were less influenced by lexicality, our results indicate that previous findings concerning VAS ratings of non-lexical CV-syllables cannot be directly transferred to the clinical context, without consideration of possible lexical bias.

In this study, we explore individual variation and contrast in Swedish children’s voiceless fricatives. Thirty-one children between three and eight years of age participated in a picture-prompted word repetition task, wherein they repeated fricative-initial words in a variety of vowel contexts. The fricatives were transcribed and acoustically analysed, using spectral moments 1–4, spectral peak and spectral balance measures. Random forests were used to estimate the relative importance of each spectral feature in the classification of correct fricative productions, as well as to measure robustness of the late-emerging contrast between sibilants [s] and [ɕ] in individual children. Transcription analysis revealed that substitutions involving a more anterior place of articulation were common. Acoustic analysis showed individual differences in variability and contrast in the children’s fricative systems across and within age groups. Cue weighting of spectral characteristics in classification was similar in all age groups for correct productions, while the magnitude of the acoustic contrast between sibilants increased with age. This paper provides a description of individual variation in Swedish children’s acquisition of fricatives which can inform future large-scale speech-acquisition research.

Voiceless fricatives are articulatorily and acoustically complex, and relatively late acquired by children. There are a plenitude of descriptions of voiceless fricatives in other languages, which have revealed language-specific patterns in realisation and acquisition. However, studies of Swedish adult’s voiceless fricatives are dated and small-scale, and knowledge concerning Swedish children’s acquisition of these complex sounds is limited.

This dissertation is based on four papers, three of which investigate acoustic characteristics of adult and child productions of Swedish voiceless fricatives /f, s, ɕ, ɧ/. Static and dynamic, individual and group-level acoustic patterns (primarily spectral features) are described, and between-fricative contrasts are quantified for individual speakers. The fourth paper explores the influence of lexical context and experience on perceptual ratings of children’s voiceless sibilant fricatives /s, ɕ/. Specifically, listeners with and without clinical experience of assessing child speech (i.e., speech-language pathologists and laypeople) provided gradient ratings of sibilants presented in lexical and non-lexical contexts (i.e., words or CV-syllables).

This work contributes to a better understanding of the characteristics and variability of /f, s, ɕ, ɧ/, and provides new insights into children’s acquisition of voiceless fricatives. A number of spectral parameters and statistical models were utilised in this work. The results of the fourth study also have relevance for perceptual assessments of speech in the clinic.

Purpose To explore Swedish clinical practice regarding assessment of suspected Speech Sound Disorders (SSD) in children.

Methods A web-based questionnaire, regarding assessment of SSD in children 4;6–6;11 (years; months), was distributed to Swedish speech-language pathologists (SLPs) through social media and online forums. The questions concerned the frequency and manner of assessment for seven assessment components, chosen based on a review of international recommendations for SSD assessment.

Results A total of 131 SLPs responded to the questionnaire. The results show that Swedish SSD assessment practices vary with regards to the frequency and manner of assessment for many components. Speech output is frequently assessed while speech perception, phonological awareness and oral-motor function are assessed less frequently. A variety of manners of assessment, for example, standardised tests, non-standardised material, and informal assessment procedures, such as observation, are utilized by respondents.

Conclusions Swedish SSD assessment practices are variable. The present paper reveals areas for development within SLP practice and education programmes, and provides a new perspective on present praxis with regards to the assessment of suspected SSD in Sweden.

Descriptions of the acoustic characteristics of Swedish voiceless fricatives are scarce and are limited to static measures derived from the speech of a small number of speakers. The current study provides an updated acoustic description of the static (spectral, temporal, and intensity) characteristics of word-initial voiceless fricatives in Central Standard Swedish. In addition, temporal variation of spectral centre of gravity is modelled using a generalized additive mixed model. Results show that fricatives were differentiated in terms of spectral properties, duration, and intensity level, such that sibilant fricatives were generally longer and more intense than non-sibilant fricatives. Spectral centre of gravity differentiated between all places of articulation apart from labio-dental /f/. Gender differences were found for centre of gravity in /s/ but overall, sex/gender differences were small. Dynamic analyses revealed differences in curvature as well as overall level of spectral centre of gravity across the duration of the fricative, associated with place of articulation and mediated by vowel context, fricative duration, and speaker specific patterns. The results from the present study are valuable for future cross-linguistic research, and as reference for investigations concerning children's acquisition of Swedish voiceless fricatives.

This paper provides a description of a current PhD project in phonetics at the Department of Linguistics at Stockholm University. A short background is pro- vided, the intended experiments are pre- sented and the potential contributions of the results are outlined.

This study aimed to investigate concerns of validity and reliability in subjective ratings of age-of-acquisition (AoA), through exploring characteristics of the individual rater. An additional aim was to validate the obtained AoA ratings against two corpora – one of child speech and one of adult speech – specifically exploring whether words over-represented in the child-speech corpus are rated with lower AoA than words characteristic of the adult-speech corpus. The results show that less than one-third of participating informants’ ratings are valid and reliable. However, individuals with high familiarity with preschool-aged children provide more valid and reliable ratings, compared to individuals who do not work with or have children of their own. The results further show a significant, age-adjacent difference in rated AoA for words from the two different corpora, thus strengthening their validity. The study provides AoA data, of high specificity, for 100 child-specific and 100 adult-specific Swedish words.