How to pronounce “imperceptibly” in English

They think they're just boring tales, but actually the magic is that they start in a really engaging interesting way so your mind is connected to it,but then slowly, imperceptibly as the story goes along, it becomes more soporific.The pauses become longer.

and the sirens and the flashing lights, zooming down 125th Street towards the Columbia campus at 60 miles an hour with the whole of Harlemout on the sidewalk watching the low profile operation ghost almost imperceptibly by.And Andrew was screaming with delight at the outrageousness of it all, "This is the best day of my life!"

I never have to call them, said Sarah.Two of them are always there, an opaque, imperceptibly moving surface that stretches away on every side, andbetrayal for which there is no evidence but of which I am entirely certain.