The Role of Sonority in Speech Sound Inventories (2013)

Undergraduate: Ivy Hauser

Faculty Advisor: Elliott Moreton
Department: Linguistics

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Although the languages of the world are diverse, there exist universal principles to which all languages adhere. For example, if a language has a [z] sound it will also have an [s]. Languages have [s] without [z] but no language has [z] without [s]. However, much is still unknown about the processes which govern the structure of speech sound inventories. In phonology, sonority (roughly correlated with relative loudness) divides speech sounds into three categories: obstruents (e.g. [p t k]), sonorants (e.g. [r l]), and vowels. The existence and importance of sonority is debated, but this project provides evidence that sonority plays a role in determining the size and structure of speech sound inventories. A statistical investigation of the sound systems of over 600 languages displayed that languages structure their sound systems according to sonority of the speech sounds. Within sonority classes, the numbers of sounds in each of its subclasses are correlated, but this correlation is lost between sonority classes. For example, the number of voiced fricatives and voiceless fricatives (both obstruent classes) are correlated, but the number of vowels a languages has is not correlated with the number of obstruents the language has. These findings have implications for theoretical phonology, giving evidence for the sonority hierarchy as a phonological feature since its existence and importance cross linguistically is debated.