Ajay Kumar Dhanapalan Email & Phone Number

San Jose, Ca, Us

Sunnyvale, Ca, Us

Sunnyvale, Ca, Us

► My key responsibilities include developing the audio front end for all Alexa enabled devices developed at Amazon Lab126. Some of the algorithm blocks include Noise Suppression, Echo Cancellation, Fixed Beamformers. Acoustic Interference Cancellers, Voice Over IP modules.► Developed a novel idea for real time audio analysis which won the 5th place in the worldwide Demo Crawl at Amazon in Seattle.► Implemented a full system architecture to handle Echo Spatial Perception that decides the device closest to the user in case of multi-device scenario.► Mentored junior engineers and provided the tools and framework necessary to efficiently deliver results.► Tackled challenges related to Whole Home Audio feature that can play audio on multiple devices connected over WiFi. ► Development framework is carried out in C++, C and Python

San Jose, Ca, Us

San Jose, Ca, Us

I was given a rare opportunity to develop audio algorithms from the core foundation. My responsibilities in this role complimented all the knowledge and hands-on experience I gained from my previous roles.► My key responsibilities included developing and implementing audio algorithms for Noise Suppression (NS), Acoustic Echo Cancellation (AEC), Automatic Speech Recognition (ASR), Keyword Detection (KWD), multimedia and low power applications.► The goals were coming up with end-to-end Noise Suppression (NS) algorithms that would reside on Digital Signal Processors (DSPs) that could be used in consumer electronics including, but not limited to Mobiles, Tablets, Televisions, Internet of Things (IoT) devices, Smartwatches, etc.,► The code optimization and porting into fixed point/floating point quantization has been carried out for several modules► Development framework is carried out in MATLAB, C and Python

Mountain View, Ca, Us

► Skipping the Algorithm Engineer III, I was directly promoted to a Senior Algorithm Engineer. The responsibilities also included leading the development as required► While in this role, I had re-vamped the training process for the machine learning algorithms like Deep Neural Net (DNN)► Carried out the training process for Machine Learning algorithms like Deep Neural Networks (DNN) and Projection to Latent Structures (PLS) regression models for estimating environmental noise. ► Worked on making updates to the existing generation of algorithm to come up with a better version to serve as the deliverable while the next generation algorithm was being implemented

Mountain View, Ca, Us

► Continuing my responsibilities as a D.S.P. Software Engineer for supporting customers, the move to the Core Algorithm Team also required me to fix the issues found during deployment. ► Closely worked with the Voice Processing Team to help develop the enhancements required for the NS/AEC algorithms to cater a major customer with a very stringent deadline. During this process, I was a part of the ‘Tiger Team’ which consisted of 6 other engineers. We not only met the deadline but, also provided a cutting edge solution to satisfy the customer requirements. ► Worked on making code changes to the existing generation of algorithms.

Mountain View, Ca, Us

► Gained hands-on experience with calibrating, tuning and making code changes to algorithms. Including but not limited to - AEC, Multi Mic Noise Suppression, Audio Focus, AGC, Voice Equalization.► Supported customers on-site with both development and tuning activities.► Represented Audience for 3 weeks at a customer site in Korea coordinating an algorithm related issues and worked closely with the HQ and the Off-Shore development center to resolve open issues in a timely manner.► Helped a team of engineers with Training the algorithm for Audio Wake feature.► Built several release firmware for Phones and Tablets.

Mountain View, Ca, Us

In less than a year with Audience, I had gained good in-sight of how the end product should be and how the algorithm is integrated along with the operating system to result in a mass production. While, I was working as a Systems Test Engineer, I started developing Algorithm specific tests to validate and characterize features like Acoustic Echo Cancellation, Noise Suppression , Automatic Gain Controllers and several other proprietary features. Based on this, the decision was made to move me into core-DSP algorithm related tests.Some of my achievements included:► Performed functionality and performance tests on the reference code in Matlab► Performed similar tests on the DSP platform and compared it to the results from the reference code.► Narrowed down issues to the module or feature and assigned it to one of algorithm, platform or firmware teams ► Enhanced and maintained a framework that automated the test execution for Matlab/TIE simulations.► Evaluated feature specific functionality and developed several test cases to test features like Multi-media, Reverberation, AGC, AEC (on board with simulated audio compensating for Latency), and enhanced tests for Noise suppression and introduced combination tests combining tow or more features aligned with use-case. Besides the features listed, I had worked on several proprietary features.► Developed an in-depth understanding of the functionality of most features mentioned above.► Developed several test scripts and generated feature specific test vectors to validate the system functionality.► Worked on evaluating different solutions offered from low-cost to the top-of-the-line.► Supported inter-team test/test development requests.► Multi-tasked and was the lead for Matlab/Platform testing.► Provided training to team members at HQ and an off-shore locations.

Mountain View, Ca, Us

After having worked with the final product testing for about 4 months as an Acoustic test Engineer, I was assigned additional duties which included FPGA/IC based testing on a proprietary development/test board. In this role, I was responsible of testing the stability, functionality and performance before the DSP processor was integrated into a mobile phone.Some achievements during this role included:► Gained hands-on experience with test equipment including but not limited to – Audio Precision, LNK for SlimBus, I2C controllers, UART controllers, multi-channel ASIO audio interfaces.► Evaluated for the algorithm performance using different metrics like G.160 and 3Quest► Worked on evaluating tests involving Sample Rate Converters, ADCs/DACs, carried out power measurements, and proprietary operating system related tests.► Found use-case related issues impacting product performance and assigned it to the respective departments using Bugzilla.► Performed detailed characterization of design, process and algorithm which was later used to validate and amend the product specifications.► Supported field engineers to narrow down several difficult to root cause bugs.► Developed Matlab scripts to automate board level tests saving several man hours and increasing the test coverage.► Updated test documentation on Confluence and Sharepoint.► Setup Test Remote Servers Stations – Hardware/Software. Used my handyman skills to put together an inexpensive and durable hardware setup for accommodating 10 Servers, Audio Interfaces, test Boards, Power Distribution Units and Audio Precision.

Mountain View, Ca, Us

As an Acoustic Test engineer, I gained hands on experience with carrier specific audio tests and product bench-marking. During this period I also developed automated data acquisition tools.Accomplishments included but were not limited to:► Developed MATLAB based tools to automate data acquisition for a multiple audio sources using switchers and Robotic Positioner which significantly reduced the time required for data acquisition.► Customized Python based test suites for Automatic Speech Recognition project to evaluate performance using Word Error Rates at different Signal to Noise Ratios across different distractors.► Collected Impulse Response using Golay Pair and simulated several acoustic conditions.► Supported Data acquisition efforts for Acoustic Echo Cancellation and a few proprietary projects.

San Jose, Ca, Us

Actively worked from February 2010 to July 2011 and continued to work/receive training and certifications during weekends and holidays until September 2012 (Immigration permitted multiple, specialization related jobs on OPT)During this period, I setup high-end audio visual equipment for various events on-campus/off-campus. This job involved working with multi-channel signal processors, amplifiers, lighting load consoles, etc.There were various workshops to help the technicians understand various aspects of sound and light. With about 20+ training modules in each of sound, light and rigging; the department also offered various supplemental training sessions like welding workshop, power tools workshop, on-campus driving safety instructions for freight vehicles, Forklift training and Current Procedural Terminology (CPT).

In

Worked an intern in the microwaves department. Carried out the design and optimization of a RF front-end for an air-borne RADAR application.

Worked on building a low noise, high gain microwave amplifier.

Master'S Degree, Electrical Engineering

B.Tech, Electronics And Communication Engineering