Bone conduction is the conduction of sound to the inner ear through the bones of the skull. Bone conduction transmission can be used with individuals with normal or impaired hearing.
Step 1: Bone Conduction: How It Works
How we Hear
Normal sound waves are actually tiny vibrations in the air. The vibrations travel through the air to our ear drums. The ear drums in turn vibrate, decoding these sound waves into a different type of vibrations that are received by the Cochlea, also known as the inner ear. The Cochlea is connected to our auditory nerve, which transmits the sounds to our brain. Protecting the Ear Drum Eardrums are extremely sensitive . Healthy eardrums allow us to hear and distinguish a variety of notes, pitches and decible levels. Listening to loud sounds – especially for an extended period of time can damage the eardrums. This is a primary source of hearing loss. Eardrum damage is cumulative and more likely to occur with old age. Listening to loud music on your iPod may seem fun when you are young, but it is likely to lead to hearing loss as you get older.
How we Hear with Bone Conduction
Bone Conduction bypasses the eardrums. In bone conduction listening, the headphones perform the role of your ear drums. Headphones decode sound waves and convert them into vibrations that can be received directly by the Cochlea – so the ear drum is never involved. Early attempts at bone conduction resulted in fairly poor sound quality. But Audio Bone has developed new technology which decodes the sound waves in high fidelity, stereo quality sound.
Bone conduction is a safer way to listen. Bone conduction does not use your eardrums, so there is less stress on your ears. Since Beethoven’s discovery, many scientists and universities have researched bone conduction, and research shows that bone conduction is safer for your ears than conventional listening.
For People with Hearing Aids
If you have experienced hearing loss, you may be able to hear clearly again with Bone Conduction. Most cases of hearing loss are due to eardrum damage. Since Bone Conduction does not use the eardrum, you may be able to listen to music clearly with Audio Bone – without a hearing aid. Many people with hearing loss report hearing high notes with Audio Bone that they could no longer hear through conventional listening.
Step 2: Circuit Diagram and It’s Requirements
Components required : –
- Piezo-Transducer – 2
- PAM8403 Audio Amplifier IC
- LM7895 – To covert 9 volt input into 5
- voltAudio Jack
- 9 volt Battery
- Connecting Wires
- Bluetooth-Module (optional)
Connections can be easily be done as shown in the circuit diagram . After completing the circuit we can get the audio input through the audio jack by inserting it in any audio generating device . Vibrations are generated on the surface of pizo-transducer that leads to generation of sound.
Step 3: Further Advancement
We can further improve the device by using a Bluetooth Module so that the signals can be transferred from audio source to our device wireless, thus making device more portable and easier to use.
we can improve the audio quality by introducing a bandpass filter which will lower the noise in our output signal.