Complex sentence: Dr. Bostwick realized that this raking movement allowed a wing to produce 14 sounds during each shake, so a bird could shaking its wings 100 times a second could produce a sound with a frequency of 1,400 cycles a second.
Split into simpler sentences: Dr. Bostwick realized that this raking movement allowed a wing to produce 14 sounds during each shake. As a result, a bird could shaking its wings 100 times a second could produce a sound with a frequency of 1,400 cycles a second.