My meaning is that the time which elapsed between seeing the flash and hearing the report was inappreciable to me. "The Ascent of the Matterhorn" by Edward Whymper

It was now dazzling, not to be looked at full; but its rate of approach was inappreciable, and as it came on I was able to peer into it and see nothing but its beauty. "Lore of Proserpine" by Maurice Hewlett