<P> Headphones ( or head - phones in the early days of telephony and radio ) are a pair of small loudspeaker drivers worn on or around the head over a user 's ears . They are electroacoustic transducers , which convert an electrical signal to a corresponding sound . Headphones let a single user listen to an audio source privately , in contrast to a loudspeaker , which emits sound into the open air for anyone nearby to hear . Headphones are also known as earspeakers , earphones or , colloquially , cans . Circumaural and supra - aural headphones use a band over the top of the head to hold the speakers in place . The other type , known as earbuds or earpieces consist of individual units that plug into the user 's ear canal . In the context of telecommunication , a headset is a combination of headphone and microphone . Headphones connect to a signal source such as an audio amplifier , radio , CD player , portable media player , mobile phone , video game console , or electronic musical instrument , either directly using a cord , or using wireless technology such as bluetooth , DECT or FM radio . The first headphones were developed in the late 19th century for use by telephone operators , to keep their hands free . Initially the audio quality was mediocre and a step forward was the invention of high fidelity headphones . </P>
<P> Headphones ( or head - phones in the early days of telephony and radio ) are a pair of small loudspeaker drivers worn on or around the head over a user 's ears . They are electroacoustic transducers , which convert an electrical signal to a corresponding sound . Headphones let a single user listen to an audio source privately , in contrast to a loudspeaker , which emits sound into the open air for anyone nearby to hear . Headphones are also known as earspeakers , earphones or , colloquially , cans . Circumaural and supra - aural headphones use a band over the top of the head to hold the speakers in place . The other type , known as earbuds or earpieces consist of individual units that plug into the user 's ear canal . In the context of telecommunication , a headset is a combination of headphone and microphone . Headphones connect to a signal source such as an audio amplifier , radio , CD player , portable media player , mobile phone , video game console , or electronic musical instrument , either directly using a cord , or using wireless technology such as bluetooth , DECT or FM radio . The first headphones were developed in the late 19th century for use by telephone operators , to keep their hands free . Initially the audio quality was mediocre and a step forward was the invention of high fidelity headphones . </P>
when was the first pair of headphones invented
when was the first pair of headphones invented
in the late 19th century
in the late 19th century