Automatic Phonetic Transcription by Phonological Derivation

Automatic phonetic transcription tools usually perform phonetic transcriptions directly from orthographic representations. Although these approaches often achieve good results, theoretical studies suggest that including morphophonological knowledge allows those systems to improve their performance. Following this idea, we developed a tool which first obtains an underlying representation of each word, using small lexica and dedicated lemmatizers. For each representation, a phonological derivation generates the phonetic transcription by applying linguistically motivated rules. Since most of these rules are added as optional parameters, the system permits to generate dialect-specific transcriptions. This system is not only a grapheme-to-phone tool, but it also obtains phonological representations and evaluates several linguistic processes occurring during the derivation. Preliminary experiments emulating a phonological system of Galician (using as input words spelled in European Portuguese) show that the underlying representation of most words can be obtained using small lexica and also that the derivation produces high-quality phonetic transcriptions.