It's pronounced with a "d" sound. It sounds exactly like the word "side".
As a rule, the past tense "ed" ending only sounds like a "t" when it follows a voiceless sound, like "roped" following the "p", or "liked" following the "k".
Hope that helps.
Thanks SL, you have been very helpful to me.Hi Nick,
In general, the sounds p, t, k, f, sh, and s are voiceless, while all vowels and other consonants are voiced, but these are the sounds, not the letters and you can't rely on crazy English spelling.
Also, some spellings like "th" can be voiced or not (voiced in "the", voiceless in "thigh").
If you go to the resources page of the forum, I believe there are sites that allow you to hear nearly any English word spoken.
Sorry I couldn't be more help.
On the topic of identifying a voiceless consonant, the simplest method is to hold your fingers against your Adam's apple (or, in the case of a female, where the Adam's apple would be if you were a male). If it vibrates when you pronounce the sound, it is 'voiced' (such as all the nasal sounds - m, n, ng), otherwise it is 'voiceless'.