I am researching dialects in Chilean Spanish , and one feature that is often mentioned (and one that you can hear all across Chile in conversation) is the varying pronunciation of the 'ch' sound. I have only a basic knowledge of the IPA from undergrad level, and I have two different papers that describe what I think is the same feature in two different ways.
A brief explanation:
1. Lower-class, stigmatised pronunciation of 'ch' in (e.g.) mucho [ʃ] (fricative, sounds like the English 'sh').
2. Middle class, standard: affricate [tʃ] or [t͡ ʃ]
(similar to 'ch' in standard English).
3. The upper-middle and upper class pronunciation is described in 2 different ways in 2 different papers. (From my time in Chile, I can describe it as more like a 'tch' sound, e.g mutcho).
as [t͡ʃ̟ ], which I read as an advanced/fronted voiceless post alveolar affricate. (2004)
as [t̚ tʃ], which I interpret as not audibly released /t/ followed by a standard /tʃ/ sound, meaning basically a longer /t/ sound in the phoneme. (1998)
So, are 4 and 5 the same sound, just described in different ways? Or are they describing different phonemes? I think 5 corresponds more closely to what I heard when I was in Chile. One possible explanation is that the phoneme has subtly evolved in the ~14 years between the two studies. As far as I'm aware this sound does not exist in English.