Editing Fis phenomenon (section)

== Experiments and studies ==
=== Covert contrast as a stage in the acquisition of phonetics and phonology ===
Scoobie et al. in 1996 looked into the notion of child perception and how they acquire their speech as well as how children contrast minimal pairs. Used Children with phonological disorders and focused on /s/ initial-stop clusters for their acquisition of them.<ref>{{Cite journal|last1=Scobbie|first1=James|last2=Gibbon|first2=Fiona|last3=Hardcastle|first3=William|last4=Fletcher|first4=Paul|date=1996|title=Covert Contrast As a Stage in the acquisition of Phonetics and Phonology|url=https://www.researchgate.net/publication/239552961|journal=QMC Working Papers in Speech and Language Sciences|volume=1}}</ref>

=== Invariant order of phonological development ===
A 1941 study by Roman Jakobson hypothesized that children who speak English follow a basic phonological order when acquiring their language's feature distinctions and, more strongly, that some elements of this order are sequential with respect to others, ''i.e.'', that for some distinctions, a child cannot fully acquire that distinction unless the child has already learned one or more some specific other distinctions. In a 1948 study, Schvachkin hypothesized that Russian-speaking children develop phonetic distinctions in an invariant order. A table is then shown where the “hushing” vs “hissing” sibilants were second to last on the order of acquisition.<ref>Moore, Timothy E. Moore (1973). ''Cognitive Development and the Acquisition of Language''. Harcourt Brace Jovanovich. pp. 215, 216, 217.</ref> Given that children are still refining and working on their phonetic production skills, it might be the case that these features are not produced accurately because previous ones still need work.

=== Juliette Blevins and claims ===
Juliette Blevins claimed that children can perceive both their own use of the language minimal pairs along with the adult usages. Though the child may believe that the subtle differences in their use of the minimal pair can be perceived by the adult, because the child themselves can recognize the differences.<ref>{{Cite book|last=Blevins, Juliette|title=Evolutionary phonology: the emergence of sound patterns|date=2007|publisher=Cambridge Univ. Press|isbn=978-0-521-04364-9|oclc=845648469}}</ref>