Four Tone Levels Register Tier Theory

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1.5.4 Register Tier Theory

In the above section, I explained the motivation for choosing features and geometry described by Snider 1999. These features and geometry work together in a system called Register Tier Theory RTT. Proposing a more complicated hierarchical geometry of tone does not change the way the autosegmental approach to tone handles tone processes. There are still one-to-many and many-to-one relationships. Tones are stable, they remain despite changes in segmental values; but, they are also mobile, they can be expressed on a different segment without changes in the segments themselves. Tones can still be floating and TBUs unassigned. Linkages can be already formed in the lexicon or assigned through processes. The difference in RTT is that now there are two features which may be involved. In this section, I summarize the implications of utilizing these features and geometry to describe a tonal system. First, I discuss how the structures described account for four levels of tones and how these relate to pitch levels, next I describe how RTT structures are used to describe autosegmental phenomena followed by a section discussing tone spreading and finally I address OCP effects in RTT.

1.5.4.1 Four Tone Levels

In order to represent four discrete level tones using Snider’s 1999 geometry, the two register features and two tonal features are combined into the four possible groupings 18. 18 Features of the four tones H Tone L Tone h Register H H h M 2 L h l Register M 1 H l L L l The geometry of the tones and features was discussed in §1.5.3.2 and was illustrated in 15. Based on the features, we expect to find natural classes in which tones which share a feature, pattern together. For example, the H and M 1 share a H Tone feature as demonstrated in 18 and therefore form a natural class. The only two groups which share no features are {H L} which is not surprising given that these are the extremes and {M 1 M 2 } which is somewhat surprising since the two levels are adjacent in the pitch scale. 26 These definitions indicate that we do not expect to find overlap in the behaviors of the M 1 and M 2 tones, nor do we expect to find ease of transition between the two. In other words, the H and the M 1 share any behaviors that are based on the H tonal melody. And the M 1 and L share behaviors based on the l tonal register. For example, a process which spreads the l-register feature causing a lowered register on an adjacent TBU can be triggered by both the Low tone and the Mid-high tone. We do not expect the H and L to share behaviors nor do we expect the M 1 and M 2 to share behaviors. The theory predicts two phonological Mid tones M 1 and M 2 which are separate and distinct. The theory predicts that a H tone could be changed to a M 2 tone by changing its register feature from h to l, or to a M 1 by changing its tonal melody feature from H to L. A M 1 could be changed to a L by changing its tonal feature from H to L or to a High by changing its register feature from l to h. But, a H cannot be changed to a L without a complete change of all of its tonal features, nor can a M 1 be changed to a M 2 without a complete change of both features. In order to determine the phonetic implications of these tonal specifications, the definitions of the features must be applied. First, the register is defined relative to the register of the previous TBU or a neutral point if the tone is utterance initial. A high register, h, is defined as being higher than the previous register, while a low register, l, is defined as being lower than the previous register. In other words, there is no fixed point in the pitch space that corresponds to register. If separate l-registers are linked in sequence although this potentially violates the OCP, the pitch will become successively lower with each new l- register. Second, the tonal melodies are relative to the register, so a high tonal melody, H, is defined as high with respect to its register and a low tonal melody, L, is defined as low with respect to its register. The phonetic height of these tones can therefore be represented as in 19. In this representation, the dashed lines represent the register features labeled with their feature designation but which are known to be higher, h, or lower, l, only by reference to the other register present while the solid lines represent the tonal features which are further described through the use of an up- or down-arrow and feature label H or L. The level of the solid horizontal line symbolizes the phonetic pitch level. 27 19 Phonetic height for four level tone phonemes Snider 1999:24. H h H L l L H M 2 M 1 L In 19, it is apparent that according to these feature specifications while M 2 occurs on the higher register, it can be phonetically lower than M 1 . The exact pitch distance between the tone’s melody features and the register features is language specific. By increasing the space between the registers and decreasing the distance between the tone and register, the two mid tones can be caused to align phonetically resulting in a system with three phonetic tone levels but four phonological descriptions, or the M 1 may be made lower than the M 2 . The interested reader is referred to Snider 1999:59-62 for a demonstration. Theoretically, every language should have access to these levels. Some languages never make use of them, in which case evoking the geometry unnecessarily complicates the phonology. In languages with downstep, the downstepped High is structurally the same as the Mid 1 . These types of languages may or may not have a lexical Mid 1 . A two tone language usually has a H on the higher register and a L on the lower register. A three tone language might have either of the two Mid tones described here. For example, in hypothetical Language A, a language with three levels of tone, both M and H tones are subject to downstep. When analyzed according to the features described here, this means that these two tones must share a h register, i.e., H is H h and M is L h. When a l register spreads, the H is downstepped to H l or M 1 phonetically and the M is downstepped to L l or L phonetically. The Mid tone in Language A is therefore a M 2 as described above. Conversely, in Language B, another language with three levels of tone, the process of downstep behaves differently. The M is not subject to downstep but instead instigates downstep of the H. Therefore, the M of Language B must be represented as a M 1 H l which does not share a h with the H tone, and is therefore not subject to downstep because it already has a l register. In this 28 language, the Mid tone is expected to form a natural class with the Low tone both of which will trigger downstep of the High tone. The four levels of tone as described in RTT have four distinct phonological representations. In some languages, like Soyaltepec Mazatec, all four levels occur lexically. In other languages only three lexical levels of tone occur, but the phonological definitions are still relevant and helpful in explaining the difference between the occurrence patterns of downstep between the two languages such as the hypothetical Language A and Language B described above. For the purposes of this dissertation, it is important to remember that each of the four levels of tone is specified for either h or l register and H or L tone, and these features are what define the phonological activity of the tones.

1.5.4.2 RTT Representations