The female pronunciation of 'son' is incorrect (she says 'sonne', without the nasal 'son'), and confuses the listener. These incorrect pronunciations by the Duo voices (not frequent, but very irritating) can be misleading and really stick in the memory, thus making it very difficult for the learner to commit the correct one to memory.
reporting does not make any sense practically. I have reported a mal pronunciation of "est" as "e-s-t" more than one year ago and it is still there.
I really appreciate the nice work from the coordinators like sitesurf and n6zs, with very appreciable attitude, good quality of replies, and rapidness to respond. I thank duolingo which helps many of us to learn new languages.
However, I really feel disappointed about the reporting system of duolingo. The audio is the essential for online learning of a language. If the errors cannot be rapidly corrected, the students are misled and the negative effects can be permanent.