I asked whether this is a real term, where it is actually used in the literature, under what other names it goes, and where it originated. At the request of one of the respondents I am posting a summary. I haven't heard the term klang association, but the phenomenon you are referring to is called sound symbolism. Symbolism in language is when there is a direct relationship between some property of the thing named and the phonetic shape of the name.
Symbolic words are common in Mesoamerican languages.
In Nahua symbolic roots based on color, motion, and other properties are found. This sounds like phonesthemes to me. Although I don't have a reference in front of me, the author to look for is Dwight Bolinger. I believe that the term was commonly used in that literature, but I don't know who coined it. Also, it might be interesting to look at what, if any, phonetic parts of the source word get retained preferentially.