The database consists of synchronised recordings of ultrasound tongue imaging and acoustic data for sixty typically developing children aged between three and thirteen years old, all speakers of Scottish Standard English. There are six tightly defined age groups: 3-year-olds, 5-year-olds, 7-year-olds, 9-year-olds, 11-year-olds, and 13-year-olds. The data, consisting of consonant-vowel syllables in a carrier phrase, were collected at Queen Margaret University, Edinburgh. The ultrasound frame rate was 100 Hz. Each participant from the 7-, 9-, 11-, and 13-year-old groups wore a custom-designed headset, which stabilised the ultrasound transducer in relation to the head. Participants from the 3- and 5-year-old groups did not wear the headset, and the transducer was hand-held by the experimenter. Additionally, each 13-year-old participant produced the same stimuli recorded without the headset. All recordings were made in a sound-treated studio, while all equipment that emitted noise was located in an adjacent room.Typically developing children generally learn to produce most vowels and consonants correctly by the age of three years old. However details concerned with complex variations of speech sound production in words and sentences (or coarticulation) continue to develop during childhood. An example of coarticulation is the difference between two realisations of the consonant /s/, in the words "sea" and "saw", which arises from the influence of the following vowel. Understanding of coarticulatory processes and the constraints on them (for example the ability to differentiate between parts of the tongue) is fundamental to our knowledge of the general processes of speech motor control. The project focusses on subtle developmental changes during childhood and preadolescent years, by collecting and analysing ultrasound imaging data on tongue position and shape in speech. The general aim is to provide articulatory and acoustic data on the maturation of lingual coarticulatory patterns and tongue differentiation from the age of 3 years old to early adolescence. The project contributes to theories of speech production, focussing on the role of tongue constraints in coarticulation development. A long-term practical aim is to gain information that will potentially be useful for diagnosing speech motor problems.

Participants’ voices and tongue movements were recorded in a sound-treated studio, using the Queen Margaret University high speed ultrasound system. The system includes customised software designed for recording, playback and analysis of synchronised ultrasound and acoustic data, Articulate Assistant Advanced (Ultrasound Module), produced by Articulate Instruments Ltd, www.articulateinstruments.com. Each participant produced eight different consonant-vowel syllables (in a carrier phrase); each target syllable was repeated around five times. The data are stored in an internal format readable only by Articulate Assistant Advanced. With the exception of 3-year-old and 13-year-old participants, the data for each group of speakers are stored in one archived file, named, e.g., “5yo.7z”). 13-year-old participants' data are split into two archived files, one corresponding to the head-stabilised recordings ("13yo_stabilised.7z"), and the other one corresponding to the handheld recordings ("13yo_handheld.7z"). 3-year-old participants' data are split into three archived files, containing the data from speakers 1 to 4, 5 to 7, and 8 to 10 ("3yo_1_2_3_4.7z", "3yo_5_6_7.7z", and "3yo_8_9_10.7z", respectively). Within each archive, the data for each speaker are contained in a dedicated folder (named, e.g., "11yo_1").