9. Dolphin echolocation is similar to ultrasound. Reflected sound waves from an object allow a dolphin to form an image of the object. Dolphins can produce sound waves with frequencies ranging from 0.25 kHz to 220 kHz, but they only use waves at the upper end of the spectrum in echolocation. Why do high frequency waves work better than low frequency waves? How does a dolphins hearing compare to a humans in terms of range? 10.Sound pulses emitted by a dolphin travel through 20 'C ocean water at a rate of 1450 m/s. In 20 'C air, these pulses travel at 342.9 m/s. How can you account for this difference in speed? 1 1. If two flutists play their instruments together at the same intensity, is the sound twice as loud as one flute playing alone? Why or why not? 12. Which of the following factors change when a sound gets louder? Which changes when a pitch gets higher? a. intensity b. speed of the sound waves c. frequency d. decibel level e. wavelength f. amplitude