This document discusses low-cost hearing aids. It begins by introducing the problem of hearing loss and how hearing aids can help provide affordable solutions. It then describes the key components of hearing aids, including microphones that convert sound to electrical signals, amplifiers that strengthen the signals, and receivers that convert the signals back to sound. The document explains the working of hearing aids in three stages: capturing sound with microphones, amplifying the signals, and delivering the amplified sound through speakers. It notes the advantages of low-cost hearing aids in providing basic amplification and accessibility. In conclusion, the document emphasizes how low-cost hearing aids can help more people experience the joy of sound.

1. Low Cost Hearing
Aid
By
NANDHINI DEVI S
20EI1042
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2. PROBLEM:
What if we lose the joy of sound at any stage of our life?
SOLUTION:
Additional help with external means is required. That is hearing aid
which are affordable for everyone to use.
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3. Introduction
• Today, we’re here to explore an important topic that touches the lives of many:
low-cost hearing aids.
• Imagine a world where the joy of sound is accessible to everyone, regardless of
their financial circumstances. This is the vision that low-cost hearing aids aim to
realize.
• In the next few minutes, we’ll delve into what low-cost hearing aids are, their
benefits, where to find them, and what to consider when seeking affordable
hearing solutions.
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4. • The principle of this project is SOUND AMPLIFICATION.
• It is the process of increasing the amplitude or loudness of an audio
signal.
• This can be done done through the use of electronics such as
transistors, amplifiers, speakers or sound system.
• The goal of sound amplification is to make the sound louder and
make easily heard by the audience.
• low velocity sound wave  AMPLIFIER higher velocity sound wave
(Input) (output)
PRINCIPLE
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5. COMPONENTS:
• ELECTRET MICROPHONE
• TRANSISTOR BC548
• TRANSISTOR BC107
• TRANSISTOR SK100
• 3.7 VOLT CELL
• POT 4.7K
• RESISTER
• CAPACITOR
• EARPHONE LED
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6. Three major sections of a hearing aid:
• MICROPHONE:to convert audio signal into electrical signals.
• AMPLIFIER:to strengthens the signals (using transistor).
• RECIEVER:to convert electric signal into sound waves.
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7. ELECTRET MICROPHONE:
• It converts audio signals to digital electrical signal.
• It has two terminals
positive terminal
negative terminal
AMPLIFIER:
TRANSISTOR BC548 TRANSISTOR BC107 TRANSISTOR SK100
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8. Working
• Capture Stage: Microphone Input
• Amplification Circuit: Enhancing the Signals
• Deliver Stage: Speaker Output
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9. Capture Stage-Microphone Input:
• The process begins with a tiny but powerful component: the
microphone.
• This microphone is strategically placed within the hearing aid to
capture incoming sounds from the environment. It acts as an auditory
“receiver,” converting sound waves – such as speech or music – into
electrical signals.
• These signals serve as the raw material for the subsequent stages.
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10. Amplification Circuit-Enhancing the Signals:
• The captured electrical signals are then sent to an amplification
circuit.
• This circuit is designed to magnify the strength of these signals,
making them more powerful and easier to detect.
• This stage is essential for individuals with hearing loss because it
compensates for their reduced ability to perceive softer sounds.
• It has 3 NPN transistors and 1 PNP transistor for amplification.
• It has a 4.7k POT connected to the collector of the sk100 transistor to
adjust the pitch of the sound.
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11. Deliver Stage- Speaker Output:
• The final stage involves converting the amplified electrical signals
back into audible sound.
• To achieve this, the device employs a small speaker or receiver
placed within or near the ear.
• This speaker transmits the amplified sound directly into the wearer’s
ear canal.
• The result is a clear and enhanced auditory experience, allowing the
wearer to engage with the world of sound once again.
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12. Circuit diagram

13. Advantages
• Affordability
• Basic Amplification
• Increased Accessibility
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14. Conclusion
In conclusion, low-cost hearing aids play a vital role in bridging the gap
between hearing loss and accessible solutions. They provide basic
amplification and improved auditory experiences to those who might
not have had the opportunity otherwise. As we work towards a more
inclusive world, let us remember that hearing is a fundamental sense
that connects us to the beauty of life’s sounds.
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15. THANK YOU