Across 5. It is the bouncing back of light as it meets a barrier. 7. It produces a stress-feeling 8. It helps bats and dolphins locate their prey. 10. The bending of light as it passes one medium to another of diferent density 11. Ray from reflecting surface. 12. Refers to the multiple echoes in a certain place 13. The property of a tone that distinguishes it from another tone of the same pitch and intensity produced by instruments down 1. The to-and-fro of a molecules and acts as a disturbance travels through a medium 2. Kind of reflection that don't produce image 3. A reflection on a smooth surface 4. The change in the frequency and oth of sound due to the movement of either the source or the istener 6. Å sound which is rellected off a surface 9. The original ray coming from the light source