a_ver a_ver knock knock who' s there
a ver a ver knock knock who' s there ?
a WORD_BOUNDARY β e̞ ɾ WORD_BOUNDARY a WORD_BOUNDARY β e̞ ɾ WORD_BOUNDARY k n o̞ k k WORD_BOUNDARY k n o̞ k k WORD_BOUNDARY w o̞ WORD_BOUNDARY s WORD_BOUNDARY t e̞ ɾ e̞ 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 ? WORD_BOUNDARY