The studies are part of a new trend: to look for integration of response rather than investigating each part/function separately. The fMRI studies show that touch has a wide impact on the brain, influencing our sensations, our movements, our thought processes and our capacity to learn new movements.
Dogs are most sensitive to sounds in the frequency range from 500 to 16kHz. REVERBERATION TIME. This is the time for a sound to decay to 60dB. Kennels by their nature have poor acoustic properties; hard, smooth surfaces do not absorb noise, therefore any noise generated tends to reverberate inside the building.
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.