Using morpheme and syllable based sub-words for polish LVCSR

Polish is a synthetic language with a high morpheme-perword ratio. It makes use of a high degree of inflection leading to high out-of-vocabulary (OOV) rates, and high Language Model (LM) perplexities. This poses a challenge for Large Vocabulary and Continuous Speech Recognition (LVCSR) systems. Here, the use of morpheme and syllable based units is investigated for building sub-lexical LMs. A different type of sub-lexical units is proposed based on combining morphemic or syllabic units with corresponding pronunciations. Thereby, a set of grapheme-phoneme pairs called graphones are used for building LMs. A relative reduction of 3.5% in Word Error Rate (WER) is obtained with respect to a traditional system based on full-words.

• Type: Journal
• Year: 2011
• Where: ICASSP
• Authors: M. Ali Basha Shaik, Amr El-Desoky Mousa, Ralf Schlüter, Hermann Ney
• Keywords: Continuous Speech Recognition, ICASSP 2011, Signal Processing, Synthetic Language, Word Error Rate