The discrete-time unit impulse is the first difference of the discrete-time step
ð ə WORD_BOUNDARY d ɪ s k ɹ iː t t aɪ m WORD_BOUNDARY j uː n ɪ t WORD_BOUNDARY ɪ m p ʌ l s WORD_BOUNDARY ɪ z WORD_BOUNDARY ð ə WORD_BOUNDARY f ɜː s t WORD_BOUNDARY d ɪ f ɹ ə n s WORD_BOUNDARY ʌ v ð ə WORD_BOUNDARY d ɪ s k ɹ iː t t aɪ m WORD_BOUNDARY s t ɛ p WORD_BOUNDARY