Does the primary distinction of retroflex consonants lie in their effect on surrounding phonemes?

Question

As an English speaker, I've had very little experience with retroflex consonants, but have recently come upon their use in Polish, and am having difficulty hearing them as particularly distinct from non-retroflex consonants at similar articulation points. In particular, I've learned that the glyph <ż> indicates the [ʐ] phoneme, but I have enormous difficulty hearing any distinction from [ʒ]. Whenever I have this impression of any sounds, my first assumption is that the distinction simply lies somewhere I'm not used to listening for, but any suggestions on what aspects of the sound I should focus on would be helpful.

On the other hand, I do notice a fairly significant change to any surrounding phonemes, especially when they are vowels. For example, if I just make the sound sequences [aʐa] followed by [aʒa] I don't notice much difference in the consonantal part of the sound, but the [a] sounds in the former are very, very noticeably retroflexed. My initial assumption is that this effect is probably more a result of my relative clumsiness and slowness in moving my tongue into retroflex position; on the other hand, it also seems possible that the primary phonemic distinction might simply involve surrounding phonemes to a greater degree than in other types of consonants. Is this off base?

Answer 1

One problem is that retroflex consonants are a disparate group, so that one might be comparing apples and oranges if you try to apply the lessons of Tamil to Polish. This dissertation by Haman gives the best overview of acoustics and perception of retroflex consonants). In the case of the unaspirated stop [ʈ], because the stop itself is just silence, ability to perceive that stop as distinct from [t] or [t̪] has to come from formant transitions to or from another vowel. Fricatives, however, have distinctive spectra, so it is possible to perceive the distinction between [ʃ] and [ʂ] just within the fricative. Since Polish retroflex consonants all have a fricative element, it is possible to hear the difference independent of formant transition.

However, as is generally true of consonants, the best cues to place of articulation come from the influence of the consonant on a neighboring vowel. At the same time, the articulation of retroflex consonants is changed as a function of the surrounding vowel.