A few keystrokes later, the speakers come to life, and the inside of the unmoving, sheltered car becomes an auditory facsimile of what it sounds like to drive through a storm: the pelting rain, the swiping windshield wipers, the engine running, the tires humming against the wet asphalt. Standing by the computers on a table against one wall, Motwani and two of his fellow Amazon engineers decide to start their demonstration at 40 mph, in the rain.

Also in the Honda are six large speakers, placed throughout the cabin. Its maker, Head Acoustics, calls it an Artificial Head Measurement System with “the acoustically relevant structures of the human anatomy,” and it’s a common tool in audio testing. The head features a black cross where a human has eyes and a nose, a pill-shaped opening for a mouth, and unsettlingly accurate, molded ears.

In the driver’s seat is what looks a bit like the upper bit of a crash test dummy, a head and shoulders mounted on a gray plastic box. For up to 18 hours on end, the dummy will talk to the Echo Auto sitting on the dash, calling out the same commands and queries over and over again.

Echo auto