Scribd
Upload
86 views12 pages

Hairing Aid Ver

This document describes a low-cost electronic circuit designed to enhance hearing for those with hearing loss. It uses a preamplifier circuit with an LM358 integrated circuit to amplify sound captured by a microphone. This signal is then sent to a TDA2822M audio amplifier integrated circuit connected to an earpiece. The circuit can be built for around $10 using readily available micro-amplifiers and components. It provides a basic amplified sound option for occasional or temporary hearing assistance until a medical-grade hearing aid can be acquired.

Uploaded by

Khadidja Khelil cherfi
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
86 views12 pages

Hairing Aid Ver

This document describes a low-cost electronic circuit designed to enhance hearing for those with hearing loss. It uses a preamplifier circuit with an LM358 integrated circuit to amplify sound captured by a microphone. This signal is then sent to a TDA2822M audio amplifier integrated circuit connected to an earpiece. The circuit can be built for around $10 using readily available micro-amplifiers and components. It provides a basic amplified sound option for occasional or temporary hearing assistance until a medical-grade hearing aid can be acquired.

Uploaded by

Khadidja Khelil cherfi
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 12

* Adad Mohamed chérif

This is a more affordable option to enhance the


hearing of a hearing-impaired person. It is not a substitute for
a genuine hearing aid prescribed by an audiologist. Medical-
grade hearing aids are quite expensive. Continuous exposure
to loud noises can result in hearing loss. The circuit we
propose could be helpful for certain types of hearing loss for
occasional use, as well as to bridge the average waiting time
for people to acquire a hearing aid.
Before explaining the functioning
principle of the entire circuit, it's
interesting to know that I took advantage of the availability of
computer micro-amplifiers on the market to use their built-in
audio amplifier to assemble my hearing aid. The total cost is quite
affordable and easy to build up .
The circuit requires only the enclosure on the left where the audio
amplifier and external buttons are located. No need for the right one.

Oon On
On/off

Volume

The 2 speakers: the left one with buit-in amplifier.


This low-cost electronic circuit operates with 3V or +5V DC. The integrated
circuit IC1 LM328 and the associated components constitute the preamplifier for the
audio signal captured by the electret microphone, transmitted to input 2 and converted
into electrical signals. Output 1 drives the input 7 of IC2 TDA2822M (green line), whose
output 3 is connected to the earpiece, see the circuit diagram. Finally, connect the power
supply +3 or 5V to 220V. It's a switching power supply available on the market and not
very expensive.
Preamplifier Amplifier

HEARING AID
The medium-power amplifier section is built around
the popular audio amplifier integrated circuit TDA2822M.
This integrated circuit, IC2, specially designed for low-power
portable applications, is readily available in an 8-pin mini
DIP package. Here, the integrated circuit is wired to drive the
general monophonic 32-ohm headphone. The audio output
of this hearing aid circuit is 10 to 15 mW, and the idle current
consumption is less than 1 mA. The circuit can be easily
assembled on a mounting board. For convenient assembly
and maintenance, use two integrated circuit sockets, a 4-pin
DIP for LM358, and an 8-pin DIP for TDA2822M.
 Upon opening the enclosure, ensure that you disconnect and set aside
the pre-existing speaker.
 Use hot glue to secure the preamplifier, the power supply and the
microphone which is inside the enclosure.
 Use a good quality mono earpiece.
LM385

TDA2822
8

Circuit pins configuration: CI1 & CI2


Préamplifier
LM358 Amplifier
Power supply 5v
TDA2822M
3 main circuits
Connection of the 3 main circuits
Exterior face of the hearing aid.

Amplifier

TDA2822M

Power
supply 5V
Preamplifier
LM358

Inside of the enclosure

You might also like