Phase is a relevant concept in the case of continuous repetitive waveforms, and has little meaning for impulsive or transient sounds where time difference is a more relevant quantity. Phase difference between signals can be caused by the time delays between them. It is usually measured in degrees relative to some reference. Assume two speakers (#1 and #2) are playing simultaneously the same sound signal around a listener, with speaker #1 placed 3 meters further away from the listener than speaker #2. Assume the sound speed is 333 meters/second. (i) Calculate the time difference between the sound signals from the two speakers arriving at the listener. Assume both speakers play a 999Hz tone. Discuss the phase relationship between the two sound signals when they reach the listener (i.e. in phase, out of phase, or partially out of phase).