Magnetic Storage. Piano wire, an electromagnet and a microphone. This was all the Danish inventor Valdemar Poulsen (1869-1942) needed in 1898 to create the telegraphone or wire recorder â the first known device capable of recording sound magnetically.agnetic Storage. Piano wire, an electromagnet and a microphone. This was all the Danish inventor Valdemar Poulsen (1869-1942) needed in 1898 to create the telegraphone or wire recorder â the first known device capable of recording sound magnetically.
And as of 2016, there are about 2.3 million home-schooled students in the United States (Brian, 2016). The studies found that of these children, 83 percent were White, 5 percent were Black, 7 percent were Hispanic, and 2 percent were Asian or Pacific Islander.
In other nations, homeschooling is considered illegal or is restricted to specific conditions, as noted in the Homeschooling international status and statistics. According to the US National Household Education Surveys, about three percent of all children in the US were homeschooled in the 2011 and 2012 school year.