Final answer:
Sound waves don't reach both ears at the exact same moment due to the different speeds at which they travel and the physical separation of our ears. This is crucial for sound localization, which our brains calculate using the interaural time difference. Furthermore, the mixed waves from multiple speakers generally create a smooth auditory experience without noticeable levels of constructive or destructive interference.
Step-by-step explanation:
Sound waves don't reach our ears at the same time due to the phenomena of sound localization. This is because sound travels at a certain speed, which is 340 m/s in air under normal conditions, and light traveling much faster. For example, in an event such as a firework display, the light reaches us almost instantly, whereas the sound takes longer depending on the distance. The ability to detect slight time differences in the arrival of sound waves enables us to locate the source of the sound. Additionally, the interaural time difference is key for sound localization. When the source of a sound is off to one side, the sound reaches the nearer ear a fraction sooner than the far ear. Our brains use this time difference to pinpoint the location of the sound. This time difference can be as little as 1.00 ms, which our ears can distinguish, and helps us understand the minimum distance sound must travel to be perceived as coming from different locations.