Harman hopes to incorporate sensors and microphones into automobiles to detect outside sounds.

To support increasingly complex audio systems and voice recognition functions, speakers and microphones have been placed in the interiors of new cars. And now, Harman is looking to put this hardware on the outside of the car as well.

At CES in Las Vegas, the Samsung-owned automotive supplier unveiled sound and vibration sensors and microphones designed to be embedded in the exterior of cars. Harman said in a press release that the sensors are sensitive enough to detect emergency vehicle sirens, the talking of other drivers and traffic cops, the sound of breaking glass, and the sound of a crash.

The hardware includes a weatherproof microphone designed to pick up speech from people outside the vehicle and a piezo-based sensor that can detect sound and vibration and convert the pressure generated into a voltage.

Harman said the sensors can be "invisibly" integrated into the exterior of a vehicle, but did not announce which automaker partners are ready to use the technology. The external sound detection is designed to complement Harman's new "Ready Vision" heads-up display, also unveiled at CES, which incorporates an audio alert to more quickly warn drivers of impending danger.

Thinner and smaller audio hardware makes such features possible, and Harman is not alone in developing them; prior to CES, LG unveiled its Thin Actuator Sound Solution technology with speakers only a few millimeters thick. According to LG, each speaker is about the same size as a passport and weighs only 1.4 ounces.

Audio systems are heavy, and weight is the enemy of efficiency and performance in automobiles; at CES 2020, automotive supplier Continental and audio company Sennheiser proposed a speakerless audio system, but the concept has yet to be commercialized. It has not yet been commercialized.