'The Unspeakableness', a project by Pei-Ying Lin, considers these strange gaps between human emotion and expression and attempts to bridge the gap with a rather lovely, slowly expanding, 'Untranslatable Words' database (http://untranslatable.peiyinglin.net/data.html). It includes videos of native speakers discussing a given word in the original language, as well as a brief attempt at an English 'definition'.
The project delves into various issues of language and translation, considering multilingualism and the association of different languages with certain emotions as well as the presence of the 'untranslatable' words, and can be found online here: http://uniquelang.peiyinglin.net/