1. A stereophonic warning apparatus for a vehicle, comprising: means for detecting objects around the vehicle and outputting signals indicative of a position of each of the detected objects; means for estimating a future position of said each of the detected objects at a future moment after a predetermined time period has passed from a detection moment at which said each of the detected objects was detected by said object detecting means, on the basis of the signals from said object detecting means, and for outputting signals indicative thereof; means for detecting a driving condition of the vehicle and outputting a signal indicative thereof; means for judging a warning priority level of said each of the detected objects according to the signals from said object detecting means and said vehicle driving condition detecting means; a plurality of speakers disposed in the vehicle; and means for controlling an output level of each of said speakers according to the signals from said position estimating means to generate a sound image including a warning sound positioned as if the warning sound originates from the future position of said each of the detected objects, said controlling means varying the warning sound according to the warning priority level in order to distinguish the respective priority levels of said each of the detected objects from each other even if a plurality of objects exist around the vehicle.