The begging of the headphones
The use of the headphones started with telephony and radio. The electrical signals of the early weak electric instruments amplification required a customized for the field of telephony.
Its use massified from emergence of personal audio systems: portable radios and portable cassette, then the phenomenon increased with the use of CD players, digital audio player, and personal computer.
Man using one of the first headphones
Woman having a conversation with headphones