what did alexander graham bell invent

Alexander Graham Bell invented several notable inventions, with the most famous being the telephone, which he patented in 1876. Besides the telephone, he also invented the harmonic telegraph, the audiometer (a device to diagnose hearing ability), an early version of the metal detector designed to locate a bullet lodged in President James A. Garfield, and the vacuum jacket, a precursor to the iron lung. Bell also developed the photophone (a device for transmitting sound on a beam of light), the graphophone (an improved phonograph using wax cylinders for better sound recording), and the aileron, a flight control surface crucial for horizontal stabilization in aircraft. These inventions have had lasting impacts in communication, medicine, and aeronautics.