  One of the challenges in automatic speech recognition is foreign words
recognition. It is observed that a speaker's pronunciation of a foreign word is
influenced by his native language knowledge, and such phenomenon is known as
the effect of language transfer. This paper focuses on examining the phonetic
effect of language transfer in automatic speech recognition. A set of lexical
rules is proposed to convert an English word into Mandarin phonetic
representation. In this way, a Mandarin lexicon can be augmented by including
English words. Hence, the Mandarin ASR system becomes capable to recognize
English words without retraining or re-estimation of the acoustic model
parameters. Using the lexicon that derived from the proposed rules, the ASR
performance of Mandarin English mixed speech is improved without harming the
accuracy of Mandarin only speech. The proposed lexical rules are generalized
and they can be directly applied to unseen English words.
