As an English-speaker, you expect a word-initial /t/ to show at least
a certain amount of aspiration (which is an external manifestation of
the extra muscular effort involved in pronouncing "fortis" sounds).
If a foreigner's /t/ is voiceless but lenis (no tension, no
aspiration), it may sound like English /d/ to your ear. English /d/
may be half-devoiced in this position, but is released without an
audible burst, which (rather than voicing alone) distinguishes it
from /t/. By contrast, in languages that rely on voicing, not
tenseness, to distinguish obstruents or languages that make use of
BOTH voicing and aspiration /d/ will always be fully voiced.
Piotr
--- In cybalist@..., markodegard@... wrote:
> I did hear a Pakistani type person say the word Daliban.
>
> I do think this pronunciation can be explained.
>
> I heard a strange T and D being neither T nor D. And yes, is was
> neither T nor D, tho' mostly D.