232 combinations are similar since the causative suffix affects the surface realization of the
preceding extension in at least some cases. However, the two combinations are different since the causative’s effects are much less with the inversive, where it only changes the
suffix following a roots. Another difference is that there is greater raising of the root vowel preceding the applicative-causative combination, whereas there is virtually no
raising of in the root or the suffix preceding the inversive-causative suffix combination.
6.7 Assimilatory effects on low vowels
As mentioned in previous sections and chapters, a is often raised when followed by high vowels, in both stems and prefixes. This is a different and in some ways more complex
issue to deal with in comparison to mid-vowel raising. The picture presented in §6.4.2 above, in which neutralization is used as the primary diagnostic for categorical
assimilation, does not work in the case of assimilation which results in a non-phonemic segment. Without a phonemic [+ATR] counterpart to the low vowel, it is difficult to
judge whether or not it has become phonologically [+ATR], or if any observed raising is simply the result of anticipatory tongue raising and is purely phonetic. This is indeed the
difficulty with many cases of a raising in African harmony systems, as in Akan e.g. Clements 1981 and Hess 1992 and Kinande see Gick et al. 2006 and references therein.
Each of these papers on Akan and Kinande exemplify the disagreements which exist concerning how to deal with a raising. Must it be dealt with in the phonology, or can it
be dismissed as purely phonetic? In Ikoma, it is clear that there is some degree of low-vowel raising. The question
is whether it is phonetic or phonological. Because raised a is not neutralizing, it is
233 harder to prove categorical assimilation. And in fact, there are a number of reasons why it
is difficult to argue for full assimilation of the low vowel. In this section, I begin with a summary of the arguments against categorical assimilation, given in 195 below.
Following this summary, I go into more detail and give examples of a number of these points.
195 Arguments for gradient not categorical assimilation of a
• Any raising before i could be attributed to anticipatory tongue height
raising, not [ATR] spreading. •
There is also gradient assimilation of and all other vowels, showing that anticipatory tongue raising is indeed a property of the language.
• There is interspeaker variation on the amount of a raising.
• Even within the speech of a single speaker, there is random variation in
the amount of raising, from word to word and repetition to repetition. •
In prefixes and augments, there could be a more robust raising effects between consonants than in word-initial position. This could explain why
raising is less consistent with the class 9 prefix a- than with the class 2 prefix a-.
• If it were categorical it would have to refer to morphology, since raising
does not happen everywhere e.g. not in some prefixes, such as class 910, so it would have to be a lexical rule. However, if it is a lexical rule,
we would expect native speakers to be aware of it, but they are not.
With these arguments in mind, I now briefly present some vowel formant analysis which explains some of the statements above. I begin with looking at a raising in verb
roots, then move to noun roots, and then look at prefixes. 196 below repeats part of the table from 167 above, showing average formant values for the three [-ATR] vowels in a
basic verb root and with the four high-vowel suffixes.
234 196
Verb root vowel averages with different verbal suffixes Speaker B
Basic CVC-a
Causative CVC-i
Passive CVC-u
Perfective CVC-i i
Agentive CVC-i
M MM
M M
MM M
M MM
M M
MM M
M MM
M M
MM M
M MM
M M
MM M
M MM
M M
MM M
476 1769
+ 3
3 +
3+ 3
467 967
33 3
3 3
637 1382
+ 03
The change of average F1 values from the basic averages are shown in 197 below. 197
Change in F1 from the basic vowel before each dominant suffix
K K
K K
K K
K K
. .
. .
K K
K K
H H
H H
K K
K K
-; . -; .
-; . -; .
K K
K K
M MM
M M
MM M
M MM
M M
MM M
M MM
M 3
+ +
3 3
The fact that there is significantly less change in F1 of and a before the subjunctive - e suffix is probably the best indicator of whether the raising is phonological and thus the
result of [ATR] spreading or if it is gradient. We have seen elsewhere that categorical raising of happens not only before i u but also before e and possible o. However,
there is only a 10 Hz difference between basic and subjunctive , and only a 33 Hz difference for a. Because the low vowel already tends to have a broad range of
acceptable values, a 33 Hz F1 difference is barely perceptible. The degree of raising is greater before the high vowel suffixes, which suggests that it very well could be a result
of tongue raising, not [ATR] spreading. In noun stems, in §4.1 we saw that a can co-occur with all other vowel
phonemes in any order. However, when followed by high vowels, a sometimes has a
235 slightly raised variant, similar to the raising with mid vowels which was described in the
previous section. The distinction is subtle, only partially predictable, and not within native speaker awareness. The following examples in 198 have a slightly raised a in
CVCV noun roots, presumably resulting from the high vowel in V2 position. 198
Raised a before i u 7
: .
2 8 8
9 -7
. 8
Long aa in V1 position is resistant to raising; when followed by i u, aa is still clearly quite low, measuring as low as nouns with a CaCa stem. We saw long-vowel resistence
to raising with the mid vowels in §4.2 as well. There is also some variation between speakers. The raising is clearer in the speech
of Speaker B than Speaker A, though that is possibly because the typical unraised a of Speaker A is higher than the average unraised a of Speaker B. Therefore, when Speaker
B’s a is raised before a high vowel, the raised variant is more easily distinguished from the unraised variant. For example, a in [e i-táti] ‘eyelid’ sounds raised in Speaker B’s
recording, but not convincingly so in the recording by Speaker A. The table in 199 shows a small sampling of words which were recorded by all four speakers in the study,
indicating which words by which speakers show evidence of raising. Words with question marks indicate cases which are difficult to determine.
236 199
Differences in low vowel raising among speakers 2 8 H
2 8 H 2 8 H
2 8 H 2 8
2 8 2 8
2 8 C C
C C
2 8 2 8
2 8 2 8
2 8 P 2 8 P
2 8 P 2 8 P
8 8
8 8
9 c
: c
c
. 8
All four words have raised a in Speaker B’s speech, whereas there is variation in which of the words sound raised in other speakers’ recordings. Because the difference is subtle,
and I have recordings for only these four words with [a…iu] for Speakers B, C and D, determining whether or not a particular vowel is raised can be difficult to say with
complete confidence. Low vowels are even less consistently raised in prefixes. A significant number of
class 2 and 910 prefix and augment vowels were measured, comparing prefixes before both [+ATR] and [-ATR] root vowels, but the results were inconclusive and quite
inconsistent. One point that was somewhat consistent is that the class 2 a- prefix vowel is more affected by [i u] in the stem than the class 910 a-, t a- prefix vowels. The
class 2 prefix vowel is also raised more than the class 2 augment, which always remains quite low. A small sample of prefix and augment vowel formant averages are given in
200 and 201 below.
237 200
Class 2 [ a-] prefix measurements before select root vowels Speaker B K
K K
K M
MM M
M MM
M A 7
A 7 A 7
A 7 8
8 8
8 +
201 Class 2 [a-] augment measurements before select root vowels Speaker B
K K
K K
M MM
M M
MM M
A 7 A 7
A 7 A 7
8 8
8 8
+33 There is a 71 Hz difference in the F1 average of the prefix vowel before [i u] and before
[ ]. It would be very difficult to argue convincingly that this level of raising is categorical, especially since low vowels in general already has such a large range of
acceptable F1 values. And concerning the augment vowel, the higher F1 values indicate that the vowel remains phonetically quite low before both [+ATR] and [-ATR] roots.
Finally, I include some data from class 910 prefixes a- and t a-. In classes 910, the prefix vowels pattern more like the class 2 augment. They resist raising, even
when directly adjacent to stem-initial high vowels. In order to get a broader picture of the lack of prefix harmony in this class pairing, I show vowel formant averages for the
prefix vowel for Speaker B in 202 below.
238 202
Class 910 prefix vowel averages before all root vowels Speaker B K
K K
K M
MM M
M MM
M A 7
A 7 A 7
A 7 8
8 8
8 +0
+3 3
+3
+3 3
Unfortunately, I had an unbalanced number of class 910 words recorded by this speaker. There were many more prefixes available before [i u] stems than before any of the other
vowels, and I was only able to measure two tokens of the prefix before [e o]. Nonetheless, we can at least get some picture of situation. Strangley, the lowest F1 value
and inversivly, the highest vowel is the prefix before [ ], which has an F1 average of 665 Hz. This is very similar to the average before [i u], which is 679 Hz. The other three
vowels, [e o a], have a similar average, at 730 and 740 Hz. We see then, that we have two different patterns emerging from the measurements, but they are not the patterns we
would expect. When we average the prefixes based on [ATR] classes, as is done in the bottom of
the table, the prefix before [ a] is indeed slightly lower than than the prefix before the [+ATR] vowels, but the difference is only 18 Hz. If we step away from average values
and begin looking at individual F1 measurements, we see that F1 values range from 584 Hz to 831 Hz, but there are many [-ATR] V1s with prefix measurements in the 600-700
Hz range, and many [+ATR] V1s with measurements in the 700-800 Hz range.
239 In summary, it is clear that some degree of low-vowel assimilation occurs,
especially in noun and verb stems. However, there is no convincing evidence which suggests that it could be categorical assimilation. Prefix raising is even less clear, once
again suggesting that low-level phonetic assimilation is the most we can confidently propose.
6.8 Summary
