Is there a word without vowel sounds?

Only in the sounds of some exclamations and onomatopoeia (natural sounds), where there is either no exhalation or very restricted airflow, e.g. sibilance.

These would be

zzz (nasal snoring sound)

mmm (lip humming)

brr (vibrating lips)

sss (sibilant hiss)

psst (truncated sibilant)

tsk (tongue cluck)

Some or all may be dictionary words (notably psst in the OED).