Bone Conduction Hearing Aid

Project 1-04 – Bone Conducting Hearing Aid 

The aim of this project is to provide assistive technology, for people who are suffering from either hearing loss or hearing impairment. We, as humans, can hear using two methods. The main method is by using the eardrum, which converts sound waves to vibrations and sends them to the cochlea. The other one is by hearing vibrations directly through the cochlea and bypassing the eardrum. Hearing disabilities are common nowadays; as about 360 million people worldwide suffer from hearing loss. There are two main types of hearing loss: sensorineural hearing loss and conductive hearing loss. Sensorineural hearing loss (SNHL) occurs when there is damage to the inner ear (cochlea), or to the nerve pathways from the inner ear to the brain. Most of the time, SNHL cannot be medically or surgically corrected. This is the most common type of permanent hearing loss. Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum. Conductive hearing loss usually involves a reduction in sound level or the ability to hear faint sounds. The main principle lies in the bone conduction transducer, which converts electrical signals to vibrations. The vibrations are transmitted through the bones all the way to the cochlea.

BCHA made three prototypes that acquire inputs using different methods. The first one uses a microphone for collecting sound waves from the surroundings and converting the sound waves into electrical signals. The signals are then amplified using a sound amplifier and transmitted to the bone conduction transducer. The bone conduction transducer converts the electrical signals to vibrations, which are carried through the bones to the cochlea. The second prototype uses a Bluetooth module to receive input from any electronic device with Bluetooth technology. The last prototype uses AUX (Auxiliary Port) technology to receive input from electronic devices that contain an audio port. Audio amplifiers and bone conduction transducers are used for the last two prototypes as well. A 3.7V 1200mAh battery is used to power the whole operation.