Voice and class size
Table 2 presents the relationship between class size and presence of a voice problem from the same group of 304 participants. A total of 49.67% of respondents reported that they had a voice problem and taught a class of >30 students. Only 7.24% of those teaching a class of >30 pupils had no voice problem. A chi-squared test was run to test the hypothesis that these variables are not related. χ2 (2; n = 304) was calculated to be 13.37, which allows us to reject this null hypothesis with an alpha level of 0.01. This indicates that voice problems were more likely to be related to a class size >30 students than not. This can be stated with 99.97% confidence and thus would indicate that a class size of >30 students is more influential on a teachers voice than overstretched work demands.