“…While 2D ultrasound has been widely used in phonetics research for many years (e.g., Gick 2002, Davidson 2002, Miller & Finch 2011, Proctor 2011, Zharkova 2013, Mielke 2015, Boyce et al 2016, Al-Tairi et al 2017, Strycharczuk & Scobbie 2017, Turton 2017, Ahn 2018, Bennett et al 2018, Tabain & Beare 2018, 3D/4D ultrasound is a relatively new technology that was originally used in speech and swallowing research by Chi-Fishman et al (2000), Bressmann et al (2007), and Bressmann (2010). Modern 3D/4D ultrasound equipment, described by Lulich et al (2018) and Lulich & Pearson (2019), has recently been used to study liquid sound articulation in American English (Berkson et al 2017), South Korean (Hwang et al 2019a;Hwang et al 2019b), and Brazilian Portuguese (Charles & Lulich 2018, 2019, as well as tongue dorsum and tongue root articulation in Arabic (Mokh et al, 2020) and Polish (Cavar et al 2017;Lulich et al 2017;Cavar et al 2020).…”