Purpose: Assessment of strained voice quality is difficult due to the weak reliability of auditory-perceptual evaluation and lack of strong acoustic correlates. This study evaluated the contributions of relative fundamental frequency (RFF) and mid-to-high frequency noise to the perception of strain. Method: Stimuli were created using recordings of speakers producing /ifi/ with a comfortable voice and with maximum vocal effort. RFF values of the comfortable voice samples were synthetically lowered, and RFF values of the maximum vocal effort samples were synthetically raised. Mid-to-high frequency noise was added to the samples. Twenty listeners rated strain in a visual sort-and-rate task. The effects of RFF modification and added noise on strain were assessed using an analysis of variance; intra- and interrater reliability were compared with and without noise. Results: Lowering RFF in the comfortable voice samples increased their perceived strain, whereas raising RFF in the maximum vocal effort samples decreased their strain. Adding noise increased strain and decreased intra- and interrater reliability relative to samples without added noise. Conclusions: Both RFF and mid-to-high frequency noise contribute to the perception of strain. The presence of dysphonia may decrease the reliability of auditory-perceptual evaluation of strain, which supports the need for complementary objective assessments.