Earphones work by converting electrical signals into sound waves using magnets and diaphragms. They have evolved from early prototypes in the 1890s to modern wired and wireless designs. Key developments included the invention of noise cancellation technology in the 1950s and the introduction of the Bluetooth standard and true wireless earphones in the late 1990s and 2010s. Future trends may include earphones embedded in VR headsets, mind-controlled earbuds, and micro-drivers attached directly to the eardrum. Earphone technology draws on principles of physics, electronics, and engineering.

1. AWAKENING THE SCIENTIST
EARPHONES
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Chembur. 2021-22
Team :-
Mohit K. Patil – CMPN - D2B , 40
Vedant V. Patil - EXTC - D4A , 42
Bhavik L. Gondhali - INST - D3 , 7
Ojas P. Patange - INST - D3 , 10

2. History Of Earphones
Invented in 1891, by Earnest Mercaider, the first earphone which was
actually patented as an ear receiver.
Modern day on-ear earphones' design was flourished in 1910. Prototype
was created by Nathaniel Baldwin for US navy to
test on communication devices.
Noise cancellation was invented in 1950s, by Dr. Lawrence J.
Fogel. This technology was specifically designed for aerospace
industry. Although the large scale production using this technology
was done by Bose Corporation after1989.
The most important aspect of the new age wired earphones, 3.5mm
jack, was first used in Sony Walkman, first portable radio.
Ya Parsan invented Bluetooth earphones in 1997.
The 3.5mm jack was a mandate until Apple Inc. Introduced TWS that is
True Wireless System based on Bluetooth, as a mainstream in 2015.
Vivekanand Education Society's Institute Of Technology,
Chembur. 2021-22

3. Principle of Operation
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 At the most basic level, an earphone is a
loop of wire with current running
through it.
 This electric current, in the loop then
interacts with a permanent magnetic
field which in turn pushes the air
producing the sound.
 Essentially earphones turn
electrical energy i.e. electrical voice
notes into sound by using magnets to
vibrate the air, creating sound.

4. Scientific Laws
1) Ohm's acoustic law :
Simply put, the human auditory system creates different sensations from a
single complex sound so that each special sound is heard clearly and can be
recognized separately.
The same process is reversed in earphones, where the different sounds, merged,
are played as a single complex sound.
2) Law of conservation of energy
It states - "Energy can neither be created nor destroyed, it can only be
transferred from one form to another."
Here the electrical energy is converted into the sound energy.
3) Law of Vibration
More the object vibrates the higher pitch sound is created.
In earphones the drivers are vibrated as needed to produce the desired sound.
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5. Engineering and Technological Aspects
 Various components like Acoustic Drivers, Audio Jack [in
case of wired earphones], Bluetooth Receivers and
Batteries [in case of wireless earphones] and wires are
assembled in a case to create a whole piece of one
earphone. Those earphones are then made usable for
normal public.
Vivekanand Education Society's Institute Of Technology,
Chembur. 2021-22
 Electroacoustic transducers, which convert an electrical
signal to a corresponding sound, are used in earphones
which let the user listen to an audio source privately.

6.  Noise Cancellation : The system collects the sound from
the surroundings through microphones that listens outside
and inside noises of earphones captures it and create
opposite sound wave that neutralise it.
 There are main two types of Noise Cancellation
1) ANC 2) Passive noise cancellation.
Vivekanand Education Society's Institute Of Technology,
Chembur. 2021-22
 Bluetooth : Bluetooth technology is basically transfer of
short-wavelength UHF radio waves of a frequency
range between 2.4 and 2.485 GHz. Transmitter is used to
send the Bluetooth waves with desired commands, while a
receiver is used to receive and further process the waves.

7. Future Trends
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v By enveloping the entire ear and removing wires or
supports one can get the bubble of surround sound
providing user an awesome experience in various purposes.
v By upcoming technology of Neuralink by Elon Musk one
can stream music directly to your brain.
Embedded earphones or micro earphones in the smart
glasses and VR headsets is the near future

8. Vivekanand Education Society's Institute Of Technology,
Chembur. 2021-22
E-Telepathy could be carried out, by which user will be
able to talk to other person just by giving signals through
brain without actually speaking by mouth.
 Mind controlled earbuds, where the earbuds will be controlled by
signals coming directly from human brain.
 A micro-driver can be attached directly to the eardrum of
human ear, which will be powered by some energy from human
body. It will directly vibrate the eardrum of ear and
the sound will be generated.

9. Domain
1) In mechanism of earphones, Physics play an important role.
The magnets are used to create permanent magnetic field which attracts and
repels the electrically charged diaphragm, which is based on physics.
The electrical energy is converted to sound energy, in which the Law of
Conservation of Energy is seen, which is Physics based.
Ohm's Acoustic Law, which explain the composition of sound, is studied in
Physics.
The transfer of electrical energy can also be studied in Physics.
2) The hardware structure of Earphones is based on BEE.
The connections done in earphones' different components are based on BEE.
The amplification of magnets in the earphones, as well as the coil used in
some earphones are based on BEE.
The transmitters and the receivers are integrated part of wireless earphones,
and are based on BEE.
Vivekanand Education Society's Institute Of Technology,
Chembur. 2021-22

10. References
History of Earphones
Types of Drivers
History of Earphones Video
How does Noise Cancellation Work
Invention and production of Noise Cancellation Technology
Everything related to Noise Cancellation
Physics behind Earphones
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Chembur. 2021-22

11. Thank You.
Vivekanand Education Society's Institute Of Technology,
Chembur. 2021-22