Improvements to the Bose Noise Canceling Headphones

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Improvements to the Bose Noise Canceling
Headphones

• Nathan Hanagami

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Project Outline

• Research available DSP and A/D Converter Units
• Implement DSP version of Corrected Compensation
  Curve
• Add features (Variable EQ/Reverb settings)
• Use spar processing power to assist in Noise
  Cancellation
• Convert Digital portions to FPGA design
• Optimizations and Work on ASIC layout

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Develop DSP

• Possible Suppliers
• Analog Devices
• TI
• Xylinx
• Linear Tech.
• Wolfson Microelectronics
• National
• Etc.

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Considerations

• Sampling Rate (Minimum 44.1 kHz)
• Sampling Width (Minimum 18 bit)
• Propagation Delay
• Power Consumption
• Physical Size
• Not as concerned about fitting on existing DSP

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Alternatives to Fitting on Chip

• Integrate EQ controller into cable for extra
  circuitry
• Design as upgrade that existing headphones can be
  plugged into (requires slightly different design
  than fully replaceable unit)

To Headphones
From Stereo
DSP
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EQ/Reverb Upgrade

• Allow user to set EQ based on Genre of Music
  (Rock, Pop, Jazz, Orchestral, etc.)
• Allow user to set Reverb to various environments
  (Concert Hall, Small room, Jazz Hall, etc.)
• Based on assumption that ideal frequency response
  varies depending on type of music.

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Assist in Noise Cancellation

• Based on meeting propagation delay requirements.
  Alternatively will layout hypothetical design
  parameters
• Work either in series to further attenuation
• In parallel to increase cancellation bandwidth

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Convert to FPGA design

• Adds Customization allowing for easier production
• Code in VHDL or Verilog
• Designed to Replace Functionality of DSP, A/D
  remain non-integrated

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Design Layout for ASIC

• Costs will probably prevent actual custom chip
  fabrication
• Work on Layout Design
• Present a hypothetical model

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Optimization

• Reduce Power Consumption
• Minimize chip area/work on layout
• Eliminate unneeded parts and minimize costs
• Work on possible improvements to analog
  amplification system

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Project Layout