Table 1.
PICOS criteria for inclusion.
Figure 1.
Flow diagram of the study identification, eligibility, and inclusion process.
Table 2.
Level of evidence by study quality score (Adapted from the GRADE Working Group, 2004 [35]).
Table 3.
Descriptive summary of extracted data from the 13 included articles.
Table 4.
Improvements in untrained measures of speech intelligibility by participant type.
Table 5.
Study validity criteria, study quality scores and levels of evidence for included articles.