Kiri T. Mealings

The Role of Utterance Length and Position in 3-Year-Olds' Production of Third Person Singular -s

PURPOSE Evidence from childrens spontaneous speech suggests that utterance length and utterance position may help explain why children omit grammatical morphemes in some contexts but not others. This study investigated whether increased utterance length (hence, increased grammatical complexity) adversely affects childrens third person singular -s production in more controlled experimental conditions. METHOD An elicited imitation task with 12 Australian English-speaking children ages 2;9 (years;months) to 3;2 (Mage = 2;11) was conducted comparing third person singular -s production in 3-word and 5-word utterances, both utterance medially (e.g., He sits back; He sits back and swings) and utterance finally (e.g., There he sits; Thats the way he sits) using a within-subjects design. Children were shown pictorial representations of each utterance on a computer and were invited to repeat 16 pseudorandomized prerecorded utterances. Acoustic analysis determined the presence/absence and duration of the third person singular morpheme. RESULTS Third person singular production was significantly lower utterance medially compared to utterance finally for the 5-word utterances and significantly lower utterance medially in the 5-word compared to 3-word utterances. CONCLUSION These results suggest that increased utterance length results in significantly lower third person singular production, but only in the more articulatorily challenging utterance-medial position. Thus, morpheme omission is greatest at the intersection of grammatical and phonological complexity.

The Development of the Mealings, Demuth, Dillon, and Buchholz Classroom Speech Perception Test

PURPOSE Open-plan classroom styles are increasingly being adopted in Australia despite evidence that their high intrusive noise levels adversely affect learning. The aim of this study was to develop a new Australian speech perception task (the Mealings, Demuth, Dillon, and Buchholz Classroom Speech Perception Test) and use it in an open-plan classroom to assess how intrusive noise affects speech perception. METHOD The first part of this article describes how the online 4-picture choice speech perception task materials were created. The second part focuses on the study involving twenty-two 5- to 6-year-old children in an open-plan classroom who completed the task while other classes engaged in quiet and noisy activities. RESULTS Childrens performance accuracy, number of responses, and speed were lower in the noisy condition compared with the quiet condition. In addition, childrens speech perception scores decreased the farther away they were seated from the loudspeaker. Overall, the children understood and were engaged in the task, demonstrating that it is an appropriate tool for assessing speech perception live in the classroom with 5- to 6-year-old children. CONCLUSIONS The results suggest that the Mealings, Demuth, Dillon, and Buchholz Classroom Speech Perception Test is a helpful tool for assessing speech perception in classrooms and that it would be beneficial to use in future research investigating how classroom design and noise affect speech perception.

The Phoneme Identification Test (PIT) for assessment of spectral and temporal discrimination skills in children: Development, normative data and test-retest reliability studies

Background: Previous research suggests that a proportion of children experiencing reading and listening difficulties may have an underlying primary deficit in the way that the central auditory nervous system analyses the perceptually important, rapidly varying, formant frequency components of speech. Purpose: The Phoneme Identification Test (PIT) was developed to investigate the ability of children to use spectro‐temporal cues to perceptually categorize speech sounds based on their rapidly changing formant frequencies. The PIT uses an adaptive two‐alternative forced‐choice procedure whereby the participant identifies a synthesized consonant‐vowel (CV) (/ba/ or /da/) syllable. CV syllables differed only in the second formant (F2) frequency along an 11‐step continuum (between 0% and 100%—representing an ideal /ba/ and /da/, respectively). The CV syllables were presented in either quiet (PIT Q) or noise at a 0 dB signal‐to‐noise ratio (PIT N). Research Design: Development of the PIT stimuli and test protocols, and collection of normative and test‐retest reliability data. Study Sample: Twelve adults (aged 23 yr 10 mo to 50 yr 9 mo, mean 32 yr 5 mo) and 137 typically developing, primary‐school children (aged 6 yr 0 mo to 12 yr 4 mo, mean 9 yr 3 mo). There were 73 males and 76 females. Data Collection and Analysis: Data were collected using a touchscreen computer. Psychometric functions were automatically fit to individual data by the PIT software. Performance was determined by the width of the continuum for which responses were neither clearly /ba/ nor /da/ (referred to as the uncertainty region [UR]). A shallower psychometric function slope reflected greater uncertainty. Age effects were determined based on raw scores. Z scores were calculated to account for the effect of age on performance. Outliers, and individual data for which the confidence interval of the UR exceeded a maximum allowable value, were removed. Nonparametric tests were used as the data were skewed toward negative performance. Results: Across participants, the median value of the F2 range that resulted in uncertain responses was 33% in quiet and 40% in noise. There was a significant effect of age on the width of this UR (p < 0.00001) in both quiet and noise, with performance becoming adult like by age 9 on the PIT Q and age 10 on the PIT N. A skewed distribution toward negative performance occurred in both quiet (p = 0.01) and noise (p = 0.006). Median UR scores were significantly wider in noise than in quiet (T = 2041, p < 0.0000001). Performance (z scores) across the two tests was significantly correlated (r = 0.36, p = 0.000009). Test‐retest z scores were significantly correlated in both quiet and noise (r = 0.4 and 0.37, respectively, p < 0.0001). Conclusions: The PIT normative data show that the ability to identify phonemes based on changes in formant transitions improves with age, and that some children in the general population have performance much worse than their age peers. In children, uncertainty increases when the stimuli are presented in noise. The test is suitable for use in planned studies in a clinical population.

The Parsing Syllable Envelopes (ParSE) test for assessment of amplitude modulation discrimination skills in children: Development, normative data and test-retest reliability studies

Background: Intensity peaks and valleys in the acoustic signal are salient cues to syllable structure, which is accepted to be a crucial early step in phonological processing. As such, the ability to detect low‐rate (envelope) modulations in signal amplitude is essential to parse an incoming speech signal into smaller phonological units. Purpose: The Parsing Syllable Envelopes (ParSE) test was developed to quantify the ability of children to recognize syllable boundaries using an amplitude modulation detection paradigm. The envelope of a 750‐msec steady‐state /a/ vowel is modulated into two or three pseudo‐syllables using notches with modulation depths varying between 0% and 100% along an 11‐step continuum. In an adaptive three‐alternative forced‐choice procedure, the participant identified whether one, two, or three pseudo‐syllables were heard. Research Design: Development of the ParSE stimuli and test protocols, and collection of normative and test‐retest reliability data. Study Sample: Eleven adults (aged 23 yr 10 mo to 50 yr 9 mo, mean 32 yr 10 mo) and 134 typically developing, primary‐school children (aged 6 yr 0 mo to 12 yr 4 mo, mean 9 yr 3 mo). There were 73 males and 72 females. Data Collection and Analysis: Data were collected using a touchscreen computer. Psychometric functions (PFs) were automatically fit to individual data by the ParSE software. Performance was related to the modulation depth at which syllables can be detected with 88% accuracy (referred to as the upper boundary of the uncertainty region [UBUR]). A shallower PF slope reflected a greater level of uncertainty. Age effects were determined based on raw scores. z Scores were calculated to account for the effect of age on performance. Outliers, and individual data for which the confidence interval of the UBUR exceeded a maximum allowable value, were removed. Nonparametric tests were used as the data were skewed toward negative performance. Results: Across participants, the performance criterion (UBUR) was met with a median modulation depth of 42%. The effect of age on the UBUR was significant (p < 0.00001). The UBUR ranged from 50% modulation depth for 6‐yr‐olds to 25% for adults. Children aged 6‐10 had significantly higher uncertainty region boundaries than adults. A skewed distribution toward negative performance occurred (p = 0.00007). There was no significant difference in performance on the ParSE between males and females (p = 0.60). Test‐retest z scores were strongly correlated (r = 0.68, p < 0.0000001). Conclusions: The ParSE normative data show that the ability to identify syllable boundaries based on changes in amplitude modulation improves with age, and that some children in the general population have performance much worse than their age peers. The test is suitable for use in planned studies in a clinical population.

An investigation into how the acoustics of different sized open plan classrooms affects speech perception in Kindergarten children

Open plan classrooms, where several classes share the same space, have recently re-emerged in Australian primary schools. This paper examined how the acoustics of four Kindergarten classrooms (an enclosed classroom (25 students), a double classroom (44 students), a linear fully open plan triple classroom (91 students), and a semi-open plan K-6 classroom (205 students)) affect speech perception. Twenty-two to 23 children in each classroom participated in an online four-picture choice speech perception task while adjacent classes engaged in quiet versus noisy activities. The noise levels recorded during the task were higher in the larger open plan classrooms compared to the smaller classrooms for both the quiet and noisy conditions. A linear mixed effects model revealed that children’s performance accuracy decreased as noise level increased. Additionally, children’s speech perception abilities decreased the further away they were seated from the loudspeaker, and this effect was stronger the higher the noise...

An investigation into the acoustics of different sized open plan and enclosed Kindergarten classrooms

Open plan classrooms, where several class bases share the same space, have recently re-emerged in Australian primary schools. This study compared the acoustics of four different Kindergarten classrooms: an enclosed classroom with 25 students, a double classroom with 44 students, a linear fully open plan triple classroom with 91 students, and a semi-open plan K-6 classroom with 205 students. Ambient noise levels, intrusive noise levels, occupied background noise levels, and teacher’s speech levels were recorded during different activities. Room impulse responses using logarithmic sweeps were also recorded for different teaching scenarios. From these recordings, signal-to-noise ratios, speech transmission index scores, and reverberation times were calculated. The results revealed much higher intrusive noise levels in the two largest open plan classrooms, resulting in signal-to-noise ratios and speech transmission index scores to be well below those recommended in classrooms with students of this age. Additi...