A stainless steel pin metal pin is a device used for fastening objects or material together, and can have three sorts of body: a shaft of a rigid inflexible material meant to be inserted in a slot, groove, or hole (as with pivots, hinges, and jigs); a shaft connected to a head and ending in a sharp tip meant to pierce one or more pieces of soft materials like cloth or paper (the straight or push pin); a single strip of a rigid but flexible material (e.g. a wire) whose length has been folded into parallel prongs in such fashion that the middle length of each curves towards the other so that, when anything is inserted between them, they act as a clamp (e.g. the bobby pin), or two strips of a rigid material bound together by a spring at one end so that, when the spring held open, one can insert some material between the prongs at the other end that, the spring allowed to close, then clamp the inserted material. According to their function, pins can be made of metals (e.g. steel, copper, or brass), wood, or plastic.
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The ear canal structure of each of us is different, and NEC's earphones make use of this. It uses a microphone to record the waveform formed by the audio noise reflected by the eardrum and uses it for identification. According to NEC, this pair of headsets can be authenticated in less than one second with an accuracy of 99%. 
NEC's New Identification Technology Analyzes Acoustic Resonance in the Ear Canal
“It implements a natural way of continuous authentication, even when moving or working, as long as wearing a headset with a built-in microphone, it can identify by listening to acoustic resonance in the ear canal.†NEC Information and Multimedia Shigeki Yamagata, general manager of the processing laboratory, introduced the introduction.
NEC said that this new technology can only use the in-ear headphones to complete the continuous identification of validators who are active or inactive. The best use is to maintain infrastructure such as medical or security and wireless confidential calls. It is unclear whether this technology has a sufficiently high signal-to-noise ratio to cope with the identification problems caused by the metabolism of the ear canal.
According to reports, NEC plans to bring products with built-in related technologies to the market by the end of 2018.
NEC's new push ear canal recognition accuracy rate of 99% is expected to enter commercial use in 2018 [Full Text]
Technology Trends In the field of science and technology, identity recognition has now become a hot research category. In addition to conventional biometric methods such as fingerprints, face, iris, speech, and retina, Japanese manufacturer NEC has recently released a new type of earplug that can perform identification by means of sound resonance in the ear canal.