[1] Univ Gothenburg, Sahlgrenska Acad, Inst Neurosci & Physiol, Dept Clin Neurosci & Rehabil,Div Speech & Languag, SE-40530 Gothenburg, Sweden
[2] Univ Schleswig Holstein, Dept Paediat, Kiel, Germany
[3] Karolinska Inst, Div Speech & Language Pathol, Dept Clin Sci Intervent & Tech, Stockholm, Sweden
[4] Karolinska Univ Hosp, Stockholm, Sweden