6. Ultrasound measuring tools can be used to quickly measure the size of rooms. These instruments work by sending out a pulse of ultrasonic sound, then measuring the time it takes for this pulse to reect off a wall and retum to the device. If you used such a device on a particularly hot day, would you measure the length of a given room to be longer or shorter than on a cool day? 11. Some bat species have auditory systems that work best over a narrow range of frequencies. To account for this, the bats adjust the sound frequencies they emit so that the returning, Doppler-shifted sound pulse is in the correct frequency range. As a bat increases its forward speed, should it increase or decrease the frequency of the emitted pulses to compensate