It is very common for a language to have different dialects or accents. The different pronunciations of the same words is one of the reasons for the different accents, in the same language. Swiss French accents have similar pronunciation to standard French, but noticeable differences in prosody. In this paper we investigate the use of standard French synthetic acoustic parameters combined with Swiss French prosody in order to evaluate the importance of prosody in modelling Swiss French accents. We use speech synthesis techniques to produce standard French pronunciation with Swiss French duration and intonation. Subjective evaluation to rate the degree of Swiss accent was conducted and showed that prosody modification alone reduces perceived difference between original Swiss accented speech and standard French coupled with original duration and intonation by 29%.