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Abstract:
Since Lieberman and Crelin (1971) postulated that Neandertals
were a speechless species, their speech capability has been a
subject of hot debates past 30 years and remains as a
controversial question. According to these two authors, the
acquisition of a low laryngeal position during the evolution is
the necessary condition to have a vowel space large enough to
realize the necessary vocalic contrasts for speech. Moreover,
Neandertals did not possess this anatomical base and therefore
could not speak, presumably causing their extinction. In this
paper, we describe biometric and acoustic studies that refute the
Liberman and Crelin's assertion. First, we show from the analysis
of MRI data that the larynx position, actually the length ratio
of the pharyngeal cavity to the oral cavity that is an
acoustically important parameter, can be estimated from
cranio-facial geometry using a linear law. Second, applying this
law, the length ratios were derived from anthropological data of
the dry craniums from the South American populations and from
Egyptian mummies. The estimated length ratios exhibit large
variations, but they also show expected age and gender trends.
Assuming the law is applicable to the Neandertals, the length
ratio and then the laryngeal position for two male Neandertal
adults was determined, which turned out to be relatively high,
but within the variation limits mentioned above. In fact, the
estimated length ratio of the Neandertals corresponds to that of
a modern female adult or of a child. Third, using an
anthropomorphic articulatory model, potentially maximum vowel
spaces on the F1-F2 plane were estimated by varying the model
morphology from a newborn (having a very short pharyngeal cavity
respect to the oral cavity, the length ratio roughly equal to
.3), a child (.6), a female adult (1.) and to a male adult
(>1.). When the calculated vowel spaces are normalized to
eliminate effects of vocal-tract size differences, the extent of
vowel spaces becomes more or less constant regardless of the
varying length ratio. We infer then that Neandertals could have a
vowel space no smaller than that of modern humans and that they
were not morphologically handicapped for speech.
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