Soru

Read the following passage adapted from an essay on the history of sound recording technology:

In 1857, French printer and bookseller Édouard-Léon Scott de Martinville patented the phonautograph, the earliest known device for recording sound. Unlike Thomas Edison, who twenty years later would invent a machine capable of both recording and playing back sound, Scott de Martinville intended his device solely to visually transcribe sound waves onto paper or glass for visual analysis. The phonautograph utilized a barrel-shaped horn to funnel sound waves toward a flexible membrane made of parchment. Attached to the membrane was a delicate stylus crafted from a pig's bristle. When sound vibrations caused the parchment membrane to oscillate, the bristle traced undulating lines onto a rotating cylinder coated with a thin layer of lampblack—a fine black soot produced by burning oil lamps.

Scott de Martinville envisioned that his recordings, termed "phonautograms," would allow scientists and musicians to read vocal performances and instrumental tones directly from paper, much like reading written text. On April 9, 1860, Scott recorded a ten-second fragment of the French folk song "Au clair de la lune," which remains the oldest known intelligible sound recording of the human voice. Because Scott never intended for the sound to be converted back into audible sound waves, his phonautograms remained silent visual artifacts for nearly a century and a half. It was not until 2008 that audio historians at First Sounds, a collaborative research project, used high-resolution digital scanning and optical imaging techniques to reconstruct the spatial tracings of the 1860 lampblack paper cylinder into an audible sound file, revealing Scott's own voice singing the ballad.

According to the passage, what specific material did Scott de Martinville use to craft the stylus attached to the parchment membrane?