Underwater illusion. One clue used by your brain to determine the direction of a source of sound is the time delay At between the arrival of the sound at the ear closer to the source and the arrival at the farther ear. Assume that the source is distant so that a wavefront from it is approximately planar when it reaches you, and let D = 0.203 m represent the separation between your ears. (a) If the source is located at angle 0 = 33.0° in front of you (the figure) and the air temperature is 20°C, what is At? (b) If you are submerged in water and the sound source is directly to your right, what is At? (c) Based on the time-delay clue, your brain interprets the submerged sound to arrive at an angle e from the forward direction. Evaluate e for fresh water at 20°C. Assume the speed of sound v in air at 20°C = 343 m/s and the speed of sound v in water at 20°C = 1482 m/s. Wavefronts.

Underwater illusion. One clue used by your brain to determine the direction of a source of sound is the time delay At between the arrival of the sound at the ear closer to the source and the arrival at the farther ear. Assume that the source is distant so that a wavefront from it is approximately planar when it reaches you, and let D = 0.203 m represent the separation between your ears. (a) If the source is located at angle 0 = 33.0° in front of you (the figure) and the air temperature is 20°C, what is At? (b) If you are submerged in water and the sound source is directly to your right, what is At? (c) Based on the time-delay clue, your brain interprets the submerged sound to arrive at an angle e from the forward direction. Evaluate e for fresh water at 20°C. Assume the speed of sound v in air at 20°C = 343 m/s and the speed of sound v in water at 20°C = 1482 m/s. Wavefronts.