This RAPID project, PI Doug Whalen, is perhaps the "last chance" to record critical phonological data on the world's only known, spoken, 3-way consonant harmony language, Tahltan. Tahltan, is a heritage language with only a few remaining speakers living (estimated 35, >67ya) on the North West Coast of Canada. Tahltan is a Northern Athabaskan language and as such closely related to the Athabaskan languages spoken in the circumpolar north. Using an ultrasound, of the same kind used in hospitals, the PI will record Tahltan speakers reading a set list of Tahltan words that will elicit consonant harmony speech situations in order to test the hypothesis put forward - that this unique 3-way consonant harmony is the result of a specific groove formation in the tongue for the three classes of consonants. This project has potential implications for a broader debate about the relationship between brain/body interactions. In addition, the proposed research will be documenting aspects of a language soon to be extinct; the project includes the participation of a university student and will provide valuable field training to the student as he/she pursues his/her science education. The project is also in cooperation with Dr. Patricia Shaw, who has worked collaboratively with the Tahltan people in documenting their language and brings those community relationships to this project.
Sounds in a language often influence each other, as when the "n" of "tenth" ends up being produced between the teeth (as the "th" is) rather than at its usual location behind the teeth. That is, the place of articulation is affects. An unusual system in which three classes of sound influence each other is found in the Athabaskan language Tahltan, spoken in northern British Columbia. Because these sounds have to agree in the place of articulation, the process is called "consonant harmony." But, unlike the English example above, the Tahltan harmony can occur across intervening vowels and, indeed, intervening consonants that are outside the three critical series. It is hard to explain how such "action at a distance can occur." However, Gafos (1996) proposed a way in which the process can be local after all: If the tongue tip shape can be maintained across the intervening segments, then the process can be seen as local. With this grant, we tested this hypothesis by measuring tongue shape in Tahltan speakers. We also compared measurements for English, which has three similar sounds ("s", "th" and "sh"). We used ultrasound to examine tongue shape during speech. The tip of the tongue is hard to image with ultrasound, but a cross-section of the tongue shows a good image of the groove down its middle. This groove varies in depth along with the tongue tip shape, so that, in the forward part of the tongue, it is shallowest for "sh," medium for "s" and deepest for "th." We found that this pattern held up, both for English and for Tahltan, in the consonants but also in the vowels in between. By applying the relatively new use of ultrasound to examine the tongue in motion during speech, we were able to support a controversial claim that places a seemingly arbitrary language process into the realm of the physiologically sensible. Gafos, A. (1996). The articulary basis of locality in phonology. Unpublished Ph.D. dissertation, Johns Hopkins University, Baltimore, MD.