a_ver a_ver knock knock who' s there
a ver a ver knock knock who' s there ?
a WORD_BOUNDARY β e ɾ WORD_BOUNDARY a WORD_BOUNDARY β e ɾ WORD_BOUNDARY k a n o k WORD_BOUNDARY k a n o k WORD_BOUNDARY w o WORD_BOUNDARY ɛ s e WORD_BOUNDARY t e ɾ e WORD_BOUNDARY
a WORD_BOUNDARY v e r WORD_BOUNDARY a WORD_BOUNDARY v e r WORD_BOUNDARY k n o c k WORD_BOUNDARY k n o c k WORD_BOUNDARY w h o ' WORD_BOUNDARY s WORD_BOUNDARY t h e r e WORD_BOUNDARY