DaimlerChrysler Corp. Joe Pompei, who developed the Audio Spotlight, shows off the system's speakers in the Dodge MAXXcab concept truck. Media Laboratory is developing a sound system that could make audio headphones obsolete. The new system, which functions something like the technology that generates low-frequency sonar beams, will direct concentrated beams of sound to individual listeners. The system concentrates sound into a narrow beam in much the same way a spotlight concentrates and projects a light beam.
Traditional speakers transmit non-directed sound at wavelengths of several feet.
This new system, called Audio Spotlight, transmits millimeter-sized, ultrasonic waves in a very narrow beam of sound, which becomes audible as it travels through the air. The signal processor and amplifier are integrated into a system about the size of a traditional audio amplifier, and they use about the same amount of power. There are two ways to use Audio Spotlight. First, it can direct sound at a specific target, creating a contained area of listening space. Second, it can bounce off of a second object, creating an audio image.