Exploring the effect of lexicality and listener experience on gradient ratings of Swedish sibilant fricatives

Figures & data

Table 1. Orthographic and phonetic transcriptions of the word pairs and extracted syllables used in the perceptual evaluation.

Word pair	English gloss	Phonetic transcription, words	Phonetic transcription, extracted syllables
“sol” – “kjol”	sun – skirt	[suːl] – [ɕuːl]	[su] – [ɕu]
“sur” – “tjur”	sour – bull	[sʉːɹ] – [ɕʉːɹ]	[sʉ] – [ɕʉ]
“Sara” – “tjat”	Sara – nagging	[sɑːɹa] – [ɕɑːt]	[sɑ] – [ɕɑ]
“sida” – “kilo”	page – kilo	[siːda] – [ɕiːlo]	[si] – [ɕi]

Table 2. An overview of the speech stimuli included in the perceptual evaluation. Note that both words and the extracted syllables are presented, although the fricative was always assigned to the same transcription category regardless of lexical context.

Transcription category	Speaker age Intended fricative										Total
	3 years /s/ /ɕ/		4 years /s/ /ɕ/		5 years /s/ /ɕ/		6 years /s/ /ɕ/		7 years /s/ /ɕ/
[s]	18	8	20	2	18	2	4	0	18	0	90
[s/ɕ]	2	12	12	20	6	10	8	8	2	0	80
[ɕ]	0	6	0	28	0	20	0	10	0	16	80

Figure 1. Spectral centre of gravity (CoG) of word-initial fricatives across transcription categories [ɕ], [s/ɕ] and [s]. Each point shows the value of one sound (total = 125).

Table 3. Description of participant demographics for the two listener groups (inexperienced listeners and SLPs).

Group	Age	Do you have children?	How often do you see children 1–6 years?
Inexperienced listeners	Mean: 33 years Min: 19 years Max: 58 years	Yes: 6 No: 21	Every day:1 Every week: 4 Every month: 3 More seldom/never: 19
	Work experience	How often do you see children with SSD?
Speech-language pathologists	<1 year: 4 1–5 years: 5 6–10 years: 6 11–15 years: 2 > 15 years: 1	Every day: 9 Every week: 6 Every month: 3 More seldom/never: 0

Figure 2. The digital VAS used in the present study.

Figure 3. Density distributions of VAS responses across all participants, separated by transcription category ([s], [ɕ] and in-between [s/ɕ]).

Figure 4. Distribution of three listeners’ ratings across the three transcription categories ([s], [ɕ] and in-between [s/ɕ]). Each point corresponds to one rating (total=250 per listener) and density is illustrated by the opacity of the points.

Figure 5. Violin plot of intrarater reliability (ICC) for SLPs and inexperienced listeners. Each point represents one individual listeners’ ICC score.

Table 4. Summary of Bayesian hypothesis tests. For each effect, the estimate $\hat{\beta }$, its standard error (SE), directional 90% Credible Intervals (CrI), Bayes Factors (BF), and posterior probabilities are listed. As is the standard for Beta regression, estimates of effects on response means are expressed in log-odd units and estimates of effects on response precision are expressed in log units.

Hypothesis	Estimate $\widehat{(\mathit{\beta }})$	SE ($\hat{\mathit{\beta }}$)	CrIlower	CrIupper	BF	Posterior probability
Mean ($\mathit{\mu }$)
Experience (SLP vs mean) > 0	0.21	0.09	0.07	0.35	155.9	0.99
Lexicality (Word vs mean) > 0	0.38	0.05	0.31	0.46	>16000	1
Lexicality × Experience (Word vs mean; SLP vs mean) < 0	−0.27	0.08	−0.39	−0.14	7999	1
Precision ($\mathit{\varphi }$)
Experience (SLP vs mean) > 0	0.46	0.21	0.12	0.80	72.1	0.99
Lexicality (Word vs mean) > 0	0.16	0.05	0.08	0.25	1453.6	1
Lexicality × Experience (Word vs mean; SLP vs mean) < 0	−0.11	0.09	−0.27	0.04	7.5	0.88

Data availability statement

The data (anonymous ratings) and code used to generate the results presented in this paper are publicly available at 10.5281/zenodo.11943307. Audio is not shared.