Sometimes. ;-) When the words really are 'worthy effort' - in, for example, 'It was
a worthy effort'.
But the words may be a mistranscription of 'worth the' - as in 'It was worth the effort'. This sort of transcription mistake is common in people who have learnt chiefly by speaking and listening, and for whom writing is a newly-acquired skill. In this case, the first 'th' is unvoiced and the second is voiced, and the two phonemes are distinct (although in practice there may be
some - incomplete - assimilation).
b