“…As shown in Table 2 , the subjects selected in the existing CSP studies were mostly adults (88.1%; Dennis and Hess, 2016 ; Wong et al, 2019 ; Chen et al, 2021 ); only few focused on children, among which four studies were on toddlers ( Thompson and Howard, 2007 ; DeVeney and Scheffel, 2019 ; Daneshi et al, 2020 ), five on pre-schoolers ( Camarata, 1993 ; Iacono, 1998 ; Girard et al, 2008 ; Kambanaros, 2014 ; Tang et al, 2019 ), one on primary school children ( Howard, 2013 ), and two on adolescents ( Musfirah et al, 2019 ; Wong et al, 2020 ). The rest were carried out with a wide age range, mainly with groups with developmental disorders; for instance, 20–85-year-old sample with neurogenic communication disorders ( Fromm et al, 2021 ), 9–16-year-old children with speech impairment ( Howard, 2004 ), 21–69-year-old adults with Parkinson’s disease ( Lee et al, 2019 ), 2–10-year-old children with Fragile X Syndrome or Down Syndrome ( Barnes et al, 2009 ), 19–74-year-old patients undergoing left hemisphere resective surgery ( McCarron et al, 2017 ), and 4–8-year-old siblings with hearing loss ( Skoruppa and Rosen, 2014 ).…”