ta-da       
exclamation  informal uk/təˈdɑː/ us/təˈdɑː/
 嗒哒,哇呀(对某事表示惊喜等)
used when something appears or happens in a way that is impressive, surprising, or pleasing
  Sit back in the seat, press the button, and ta-da! It's a bed! 靠着坐在座位上,按一下按钮,然后嗒哒!原来 是一张床!  
"Ta-da!" Rosemary announced as she brought in the birthday cake. "嗒哒!" 罗斯玛丽一边大声说着,一边把生日蛋糕拿了进来。 
 - More examples
 - A rock can be lifted away and - ta-da ! - colourful fish swim out.
 - I called up the calculator function of my maths program, typed in the numbers, and ta-da! There was the answer.
 - Sarah scurries off to a kitchen area and returns - ta-da ! - with a large hot-food pan.
 - Ta-da! Now you can click, drag, and generally perform tasks on the computer remotely, as if it were right in front of you.