Laryngeal theory

Hypothesis that Proto-Indo-European had phonemes beyond those reconstructed through comparison

The laryngeal theory is a theory in historical linguistics positing that the Proto-Indo-European language included a number of laryngeal consonants that are not reconstructable by direct application of the comparative method to the Indo-European family. The "missing" sounds remain consonants of an indeterminate place of articulation towards the back of the mouth, though further information is difficult to derive. Proponents aim to use the theory to:Produce greater regularity in the reconstruction of PIE phonology than from the reconstruction that is produced by the comparative method. Extend the general occurrence of the Indo-European ablaut to syllables with reconstructed vowel phonemes other than *e or *o.

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