An "external microphone" refers to a separate microphone that can be connected to a device, such as a camera or computer, to improve the quality of audio recordings. Full definition
But don't rush out to buy an expensive external microphone just yet, because your smartphone has all of the necessary hardware already. (android.gadgethacks.com)
Students use the iPods with external microphones to record their reading practice and assessments. (edutopia.org)
We'll teach you how to forward calls to your landline or mobile phone, use external microphones and cameras, disable its typing indicator and more. (laptopmag.com)