Feature representations


We assume a feature classification in terms of multivalued features or tiers as defined in the following table.

Figure 4: Default word structure for English and German
Tier Features
phonation {voiced, voiceless}
manner {plosive, fricative, nasal, lateral, vowellike}
place {labial, alveolar, palato-alveolar, velar, palatal, uvular, glottal}
v-place {front, back, central}
height {high, low, mid}
length {long, short, lax, tense}
roundness {round, nonround}
The notion of tier will be discussed in more detail in the next section. For now it is sufficient to assume that tier refers to an attribute or type of feature whereas the value of this attribute may be one of a number of features. On the basis of this feature classification, we can define the following general description of vowels:


    <> == Null
    <place>     == "<v-place>"
    <phonation> == [voiced]
    <manner>    == [vowellike]
    <v-place>   == [central]
    <height>    == [mid]
    <roundness> == [nonround]
    <length>    == [lax]
    <featural>  == [ "<phonation>" "<manner>" 
                     "<place>" "<height>" 
                     "<roundness>" "<length>" ].
This node defines a featural template for vowels in terms of attributes or tiers and feature of value specifications for these attributes. Information about the phonemic segment is also provided for the individual vowels. We assume the neutral central vowel schwa ([@]) to be the default case. Other vowels differ from the neutral vowel with respect to vowel place, height, roundness or length.

    <> == V
    <segmental> == @.
    <> == V
    <height>    == [low]
    <segmental> == 6.
    <> == V
    <v-place>   == [front]
    <segmental> == E.
    <> == V_E
    <length>    == [tense]
    <segmental> == e:.
    <> == V
    <v-place>   == [back]
    <height>    == [mid]
    <roundness> == [round]
    <segmental> == O.
A featural template for consonants may be defined in a similar manner. In this case the default consonant is taken to be [z] since for German at least, this leads to the most economic representation. Other consonants are defined on the basis of this default. Thus, for example, the definition of the segment [d] only requires an equation specifying the value of manner to be plosive since all other feature values are inherited from the specification of the default.
    <> == Null
    <phonation> == [voiced]
    <manner>    == [fricative]
    <place>     == [alveolar]
    <featural>  == [ "<phonation>" "<manner>" "<place>" ].
    <> == C
    <segmental> == z.
    <> == C
    <manner>    == [plosive]
    <segmental> == d.
    <> == C_d
    <phonation> == [voiceless]
    <segmental> == t.
    <> == C_t
    <place>     == [velar]
    <segmental> == k.
In what follows, we assume the syllable structure in terms of onset, peak and coda which we defined in the syllable structure. However, we must now also take the more detailed phonotactic structure into account. In German phonotactics, for example, syllables have the canonical form C${\sf_0}{\sf^3}$V${\sf_1}{\sf^2}$C${\sf_0}{\sf^5}$.This says that a syllable can have up to three consonants in the onset, one or two vowels in the peak and up to five consonants in the coda. We represent this as follows:
    <> == Null
    <structure> == I[ <onset> II <peak> II <coda> I]
    <onset> == "<phn onset first>"
               "<phn onset second>"
               "<phn onset third>"
    <peak>  == "<phn peak first>"
               "<phn peak second>"
    <coda>  == "<phn coda first>"
               "<phn coda second>"
               "<phn coda third>"
               "<phn coda fourth>"
               "<phn coda fifth>".
If we want a fully structured featural representation then we can obtain it from the value of the <structure featural> path, whereas if we want a traditional unstructured phonemic representation (in SAMPA ) then we can obtain it from the value of the <structure segmental> path. For this to work as we intend, we need to define the three utility punctuation nodes invoked in the equation for <structure> above. Dealing with the formal language punctuation in this indirect way may seem unintuitive but it has the advantage that one can make the format of the punctuation sensitive to the type of information requested.
    <> == Null
    <structure featural>  == I] I[.
    <> == II
    <structure featural>  == [
    <structure segmental> == /.
    <> == I[
    <structure featural>  == ].
Syllable entries in the lexicon inherit default information from the general Syllable node which defines the syllable structure in terms of onset, peak and coda. Specific information as to which segments make up the syllable are defined in the individual entries by rules of referral.

We can now define syllable entries in our lexicon. The example entries shown here are the syllables /te:/, /E6/ and /dOk/.

    <> == Syllable
    <phn onset first> == "C_t:<>"
    <phn peak first>  == "V_ee:<>".
    <> == Syllable
    <phn peak first>  == "V_E:<>"
    <phn peak second> == "V_6:<>".
    <> == Syllable
    <phn onset first> == "C_d:<>"
    <phn peak first>  == "V_O:<>"
    <phn coda first>  == "C_k:<>".
From these node definitions, taken together with the axioms for syllable structure, we can now infer the following phonemic and feature representations for the syllable /te:/, for example:
    <structure segmental> = / t e: /
    <structure featural>  = [ [ [voiceless] [plosive]
                                [alveolar] ] ]
                            [ [ [voiced] [vowellike]
                                [front] [mid] [nonround]
                                [tense]  ] ].
We omit the empty segments (i.e., the second and third positions of the onset, the second peak slot, and the complete coda). They can easily be removed using a technique which will be described in more detail in the section on time map domains, below.

Exercise 6043

Define further consonant and vowel segments which are relevant for German. Use them to define a ten segment syllable. Show the implied feature representation for this syllable.


Exercise 6044

In the light of the analysis of German vowels and consonants presented in this section, develop a comparable analysis for English.


Nonsegmental phonology (back)