This paper investigates the challenges in building Swiss German speech
translation systems, specifically focusing on the impact of dialect diversity
and differences between Swiss German and Standard German. Swiss German is a
spoken language with no formal writing system, it comprises many diverse
dialects and is a low-resource language with only around 5 million speakers.
The study is guided by two key research questions: how does the inclusion and
exclusion of dialects during the training of speech translation models for
Swiss German impact the performance on specific dialects, and how do the
differences between Swiss German and Standard German impact the performance of
the systems? We show that dialect diversity and linguistic differences pose
significant challenges to Swiss German speech translation, which is in line
with linguistic hypotheses derived from empirical investigations