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Background  Goal  Functional  Requirements  Specifications  Constraints



      EarTalk is a wireless communication device used in high-noise environments where hearing protection is necessary. The current EarTalk system consists of a microphone and a speaker embedded in separate earplugs along with external circuitry to restore the natural quality of the userís voice.  This current system is too large and uses wires to connect to the microphone/speaker.

      The Center for Disease Control (CDC) in Cincinnati, Ohio created the current EarTalk system.  The microphone embedded in the earplug senses the userís voice through bone vibrations in the head, converts it to an electrical signal, and then sends the signal via wire to a 2-way radio. The CDC is collaborating with AudioVibe to create a wireless EarTalk system.  This wireless system will provide a clear, discrete method of communication for use in high-noise environments.  Clear communication is critical in applications such as firefighting where it can mean the difference between life and death.


Goal   Back to top

      The goal of this project is to design and implement a low-power, compact wireless circuit to transmit speech from the userís ear to a re-transmitter approximately 5 to 8 inches away from the ear.  This circuit should be small enough to fit within the earplug and send the userís voice signal to a relaying transmitter on the user's helmet.


Functional Requirements   Back to top


1)  Sense and convert speech inside ear
Must sense speech from inside the ear canal and convert the acoustic signal to an electrical signal.
2)  Wireless
Must transmit signal from the ear to a re-transmitter wirelessly.
3)  Low power
Must operate on a minimal amount of power.


Specifications   Back to top

1)  Sense and convert speech inside ear
Transducer, circuit, and battery must be small enough to fit in or closely around the ear and provide a good quality acoustic to electric conversion.
2)  Wireless
Must transmit signal wirelessly from ear to a re-transmitter approximately 5-10 inches away.
3)  Low power
Must remain operational for no less than 10 hours with a 1.3-volt hearing aid battery.


Constraints   Back to top

A.  Configuration
The instrumented earplug should fit entirely within the ear with little or no protrusion outside the ear.
B.  Transducer
A low-power transducer should be used.  Avoid electromagnetic loudspeakers because they consume a relatively large amount of power.
C.  Modulation technique and carrier frequency No constraints.  However, factors such as channel noise, helmet material, transmission distance, etc. should be considered.


E.  Antenna


Due to space limitations, an antenna should be very small or non-existent.


© Team AudioVibe - University of Idaho 2004-2005

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