Carpi’s Voice Rectifier

A beautiful or not-so-beautiful voice can be made more beautiful by sticking Carpi’s voice rectifier in one’s mouth, perhaps. The well-more-than-century-old device is enshrined in a patent: “Voice Rectifier,” US patent 527235, granted to Vittorio Carpi, 1894. Carpi explains: Be it known that I, VITTORIO CARPI, of Chicago, in the county of Cook and State […]

Improbable Research