01 NRDC Dyslexia 1-88 update - Texthelp

Developmental dyslexia in adults: a research review 45
Over time, too, the most appropriate measures of phonological awareness may change
(Schatschneider et al., 1999). Learners begin to acquire phonological awareness when they
learn to separate word units in the speech continuum, to hear the two parts of a compound
word, to separate the syllables of a word, to select rhyme-words and to hear which words
start with the same or different sounds (Goswami & Bryant, 1990; Sodoro et al., 2002). In its
most complete sense, phonological awareness is neither innate nor acquired spontaneously
in the course of cognitive development (Morais et al., 1979). ‘Discovering phonemic units is
helped greatly by explicit instruction in how the system works’ (Ehri et al., 2001); moreover, it
is optimally taught in the context of reading instruction (Hatcher et al., 1994).
The importance of tuition becomes clear when we acknowledge that phonemic awareness—
the insight that every spoken word can be conceived as a sequence of phonemes (the smallest
units of language that distinguish one word from another) —differs from less fine-grained
aspects of phonological awareness (such as syllable counting and rhyme recognition). To
develop the phonemic awareness that reading and writing call for, students must learn to put
their attention where it had never had to be and learn to attend to meaningless phonemes,
not meaningful morphemes and words: ‘Speech does not require phonemic awareness for the
same reason that it does not produce it’ (Liberman & Whalen, 2000). Our acknowledgement is
underlined by the recognition that discovering phonemic units is helped by, or even
conditional upon, explicit instruction in their isolation, identity, categorisation, blending,
segmentation and deletion (Alegria et al., 1982; Cardoso-Martins, 2001; Ehri et al., 2001) and
explicit instruction in letter-sound relationships.
Phonemes themselves are abstractions: they do not exist as part of the acoustic speech
signal (Baudouin de Courtenay, 1895; Liberman & Whalen, 2000; Nittrouer, 2002). While it is
true that speech is a stream of vocal sounds, we learn to analyse this sound-stream as a
sequence of linguistic units; in the normal course of events, we learn to recognise words and
syllables before we first go to school and we learn to recognise phonemes as we are taught to
read and spell. Each phoneme is a set of similar (but audibly different) sounds, or ‘phones’,
like the sounds represented by the letter ‘p’ in ‘pot’ (where it is followed by a puff of air) and
in ‘spot’ (where it isn’t), so that a phoneme is both a percept and a concept (Gleitman & Rozin,
1977). For reading and spelling, it is less a noise in the ear than an idea in the mind (Baudouin
de Courtenay, 1895).
In English, especially, the correspondences between phonemes and graphemes (the letters or
letter-groups used to transcribe phonemes) are complex (Jackson & Coltheart, 2001). For
most people, learning to read offers the only opportunity to gain insight into the phonological
structure of speech; if people are not taught, they may never intuit this structure (Liberman,
1998; Morais et al., 1979). The method by which learners are taught to read may influence the
development of phonemic awareness (Alegria et al., 1982), but the whole-word method is not
incompatible with the development of phonemic awareness (Leybaert & Content, 1995) and
neither do phonics methods guarantee that development (Vellutino et al., 1996).
A useful distinction can be made between sensitivity to phonemes and the ability to analyse
(or manipulate) them (Mann, 1987). Then, if phonemic awareness is defined as conscious
access to the phonemic level of the speech stream (Stanovich, 1986), a lack of phonemic
awareness need not imply any substantial inferiority in phonemic sensitivity (Adrián et al.,
1995) and would not be sufficient evidence for a cognitive dysfunction. Indeed, the growth of
phonemic sensitivity is a developmental imperative. Since the acoustic signal of speech lacks
invariant physical correlates to phonetic segments and the ability to recognise segmental