1Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Team Acoustic Beamformer

Preliminary Design Review

10/18/2013

2Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Team Acoustic Beamformer

Nick DriscollEE

Rebecca McFarlandCSE

John ShattuckEE

Jimmy DanisEE

Name

3Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Presentation Overview• Problem Statement• Social Impact• Our Project: The Acoustic Beamformer

• System Requirements• Block Diagram• Description of Components

• Alternatives• Current Development Status• MDR Deliverables• Schedule

4Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Problem Statement• Difficult to scan and localize a single person’s voice

among outside conversation and background noise in real time

5Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Problem Areas• Primary: Conference

Rooms/Small Lecture Halls• Video conferences across

business sites• Questions asked in lecture

• Secondary: Surveillance• Detecting noises in small rooms• Would be nice for surveillance

cameras to quickly point to an intruding noise source

6Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Social Relevance• Hard for those with hearing impairments to filter

out background noise• Cost considerations

• High-end hearing aids can cost up to $8000• Up to 75% of hearing-impaired individuals do not have

hearing aids

7Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Solution: The Acoustic Beamformer

Input: 8 microphone outputs

Output: Project audio signal and visual representation of sound wave

Utilize Beamforming Signal Processing Techniques

8Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

System Requirements• Operate within the human voice frequency

spectrum• Ideally 300 Hz- 3kHz

• Localize a sound source within 5 meters of the microphone array (15 feet)

• Effective in an 100 degree span15 ft.

40o(Not to Scale)

9Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Final System FunctionalityInitial Goal:

• Manually input desired target angle into the PCOptimal Goal:• Scan, find and fixate on individual sound sources

within our 100o span• Alternative: Identify an electronic “bug” emitting a high

frequency sound (15kHz) to fixate on

10Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Block Diagram

11Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Microphones• Analog Device MEMS Microphone• Omnidirectional• Analog output• Frequency range: 100 Hz – 15 kHz• Sensitivity -42 dB +/- 3 db @ 94 dB SPL• S/N Ratio 62 dB

12Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

A-D Converter• Need 8 channel inputs• Need USB out because modern computers do not

support serial interfaces• Options we are investigating:

MC USB-DIO24/37 DATAQ DI-149 USB

13Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Computer Software• MATLAB for simulation and initial analysis• Custom software for real-time processing

• DSP processing library• Visualization • Audio output

14Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Alternatives: Nontechnical• Direction of interest manually fixated

• Pass around a microphone• Physically turn a microphone or camera to target point• Cheap and accessible

Inefficient, more time consuming than electronic methods

15Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Alternatives: Technical• ClearOne non-directional 24 microphone array

for conference rooms• Price: $3,000

• Polycom HDX Ceiling Microphone Array• Price: $1,200

Systems are expensive, far exceeding an SDP budget

16Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Current Development Status• Researched similar previous SDP projects

• 3 main issues keeping others from succeeding:• Problems integrating A/D Converters• Choosing substandard microphones• Assuming plane waves (sources likely too close)

• Compiled several MATLAB simulations• Refining a basic algorithm for use• Purchased a few microphones for initial testing before

deciding on final hardware

17Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

MATLAB Plots

18Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

MATLAB – Source Angle Sweep

19Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Proposed MDR Deliverables• Single microphone to A-D • Input into MATLAB• Be able to analyze one channel in MATLAB• Parallel development of real-time software framework

20Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

ScheduleTask Area Responsible Due DateTest mics - determine if they meet specs Hardware Nick 18-OctChoose A-D Hardware Nick 1-NovInitial MATLAB simulations MATLAB Jimmy 6-OctMATLAB Parameter Sweep MATLAB Jimmy 6-OctMATLAB Parameter Optimization MATLAB Jimmy 10-OctMATLAB Source Scan MATLAB Jimmy 18-OctMATLAB Source Track MATLAB Jimmy 18-OctFind DSP library Software Rebecca 18-OctDesign software structure Software Rebecca 18-OctTest A-D into computer Hardware Nick 8-NovProcess signal in software Software Rebecca 1-NovProcess multiple inputs in software Software Rebecca 15-NovGet signal->computer & see in MATLAB MATLAB General MDRMDR Review Week Misc 18-NovMDR Draft Report Documentation Jimmy 27-NovMDR Final Report Documentation John 13-DecAlgorithm Design Misc John Ongoing

21Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Backup Information

22Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Mic Separation Sweep

23Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Zink

Source Frequency Sweep