Variations of vocal effort are a normal adaptation to difficult communication situations. However, persistence of these abnormal strategies can lead to various functional dysphonias. In this experiment, the authors tested 41 females aged 18-52. The subjects were asked to instruct one of the examiners into adopting certain positions according to cue cards. In the control situation, the distance between the subject and the examiner was two metres, but in the testing position, the distance was increased to 15 metres and an additional ‘stress’ constraint was introduced by asking the subject to instruct the examiner to adopt as many positions as possible in 90 seconds. All participants were subjected to the Neo five factor inventory (NEO-FFI-R) personality questionnaire which classifies personality traits into five categories (openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism). All test subjects showed an increase in vocal intensity (from 75.5dB to 81.8dB) and an increase in the first formant or the basal frequency for each person (from 249.4Hz to 335.8Hz). Both increases were statistically significant. However, there were no statistically significant differences between different personality traits in this change in the vocal effort. This preliminary study demonstrated that physical and emotional constraints contribute to vocal strain. Further studies are needed to correlate personality traits with other aspects of vocal production, such as respiratory effort or posture. This would be beneficial in the elaboration of personalised voice training for functional dysphonias.