The beginnings of Recorded Sound

1. The beginnings of Recorded Sound

2. The Electromagnet • In 1825, British inventor William Sturgeon (1783-1850) revealed an invention that laid the foundations for a large scale evolution in electronic communications: the electromagnet. • Sturgeon displayed the power of the electromagnet by lifting nine pounds with a seven-ounce piece of iron wrapped with wires through which the current of a single cell battery was sent. • NOTE: 1825 William Sturgeon invented the electromagnet

3. The Telegraph • In 1830, an American, Joseph Henry (1797-1878), demonstrated the potential of William Sturgeon's electromagnet for long distance communication by sending an electronic current over one mile of wire to activate an electromagnet which caused a bell to strike.

4. However, it was Samuel Morse (1791-1872) that successfully exploited the electromagnet and bettered Joseph Henry's invention. Morse invented a telegraph system that was a practical and commercial success. • In 1838 He used pulses of current to deflect an electromagnet, which moved a marker to produce written codes on a strip of paper - the invention of Morse Code. The following year, the device was modified to emboss the paper with dots and dashes. • NOTE: Samuel Morse creates the telegraph and the “dot and dash” Morse Code.

5. The first machine recording voice was called phonograph. It was developed as a result of Thomas Edison's work on two other inventions: the telegraph and the telephone. Edison was working on a machine that would transcribe telegraphic messages on paper tape, which could later be sent over the telegraph repeatedly.

6. This development led Edison to speculate that a telephone message could also be recorded in a similar fashion. He began experimenting with the diaphragm of a telephone receiver by attaching a needle to it. He reasoned that the needle could prick paper tape to record a message. In 1877 his experiments led him to try a stylus on a tinfoil cylinder, which, to his great surprise, played back the short message he recorded, "Mary had a little lamb."

8. Edison did no further work on the phonograph for a while, concentrating instead on the light bulb. And so others moved forward to improve on his invention, including Chichester A. Bell and Charles Sumner Tainter, who developed a wax cylinder for the phonograph. In 1887 Edison resumed work on his phonograph and used wax cylinders too. These early cylinders had two significant problems. • The short length of the cylinders, only 2 minutes. • There was that no mass method of duplicating cylinders.

9. In 1895 Emile Berliner revolutionized the future of recorded sound. • Berliner's gramophone differed its contemporaries in that it used a flat shellac disc to record sound rather then the cylinder proposed by Edison. The disc permitted mass duplication and playing time was 4 minutes.

11. Fast forward • The first disc recorded by electrical equipment :1920 • Gramophones turned by electricity (instead spring motors) :1925. • First “long playing” discs (knows as LP's) :1904 • 1931 standard speed 33.3 r.p.m. • The shellac discs, which were Brittle,  were replaced in 1946 by plastic ones. • micro-grove discs :1948.

13. Why Different Speeds? • Emil Berliner determined roughly how fast old disc records should spin. • He avoided Edison's need for a stylus made from precious jewels by using points which could be made from steel sewing needles and pins. • The size of the stylus effectively determined the size of the grooves in a record and the recordable frequency range limited by this groove size determined a speed between 70 and 90 rpm