World's Ten Most Colorful Flags. Here are ten of the most colorful flags from around the world. While it is fairly common for flags to have just three colors, like the red, white, and blue of the United States or the black, red, and gold of Germany, some flags are much more colorful than that. What makes a flag colorful tends to be a subjective decision, however.
The wind noise spectrum is dominated by the lower. frequencies (< 500 Hz), although at 27 mph when. saturation is present, the wind noise level can be greater. than 60 dB SPL at 8 kHz. It is clear that wind noise is at. high levels at commonly encountered wind speeds and. needs to be suppressed.
This depends on the frequency of the whistle (I'm simplifying by assuming a single-tone whistle). The frequency of dog whistles is between 23 and 54 kHz [1]. This is a pretty wide range; I doubt that there is any non-trivial number of humans able to hear 54kHz, but 23kHz is within hearing range of most children. With age, as eardrums become larger and less flexible, sensitivity to higher frequencies drops off.