Estevan Valencia Rivera
Oceanside
Summary
Dynamic Audio Systems Engineer with over 3 years of specialized experience in speech enhancement, signal processing, and AI-driven audio technologies. Proven expertise in conducting subjective listening evaluations to inform model selection, complemented by a strong foundation in MATLAB and Python scripting, as well as C and C++ programming. Skilled in integrating custom audio solutions into real-time communication platforms while performing comprehensive subjective performance assessments to drive model refinement. Committed to advancing the field of audio signal processing through innovative research and practical implementation strategies.
Overview
8
8
years of professional experience
Work History
Speech R&D Engineer
Qualcomm
San Diego, CA
01.2025 - Current
- Ported PyTorch inference graphs to a custom C runtime for an AI low‑bitrate audio codec, translating ops, quantization, and tensor layouts while preserving numerical stability
- Built C implementations and unit tests for key model components
- Validated model parity by comparing C vs. Python outputs, enforcing SNR thresholds
- Evaluated multiple open-source softphones and media stacks, selecting Linphone for its jitter buffer management (JBM) and robust packet loss handling to support realistic network conditions
- Integrated the in-house codec into Linphone, replacing the default codec path and adapting RTP/packetization, payload types, and jitter buffer interactions for seamless VoIP playback
- Delivered an end-to-end demo application (call setup, encode/decode, packet loss scenarios), enabling stakeholders to assess codec performance under real-world conditions
- Ran objective audio quality metrics to shortlist top-performing models across bitrates and channel conditions
- Designed and executed double-blind listening tests, synthesizing subjective scores with objective metrics to select production candidates
Audio Systems Test Engineer
Qualcomm
San Deigo, CA
05.2022 - 10.2024
- Performed audio tuning on Qualcomm’s prototype hardware platforms to achieve highest AI Echo Cancellation Noise Suppression performance.
- Created a repeatable process for collecting speech data for AI model training using a MATLAB based app.
- Implemented a C Code DoA histogram to filter DoA data for AI-Director.
- Helped tune and test AI ECNS on Snapdragon Xelite laptops for DXOMark and internal demos.
- Helped pass Microsoft Teams certification for IoT Soundbars.
- Conducted competitive analysis on Mobile, Compute, XR and Watch platforms for AI ECNS technology.
- Developed Linear Echo Cancellation filter in MATLAB used for creating data for AI models.
- Conducted 3GPP certification testing on mobile platform.
Energy Management Data Analyst Intern
University of California, Riverside
08.2018 - 06.2020
- I work in the Energy Management office at UCR creating energy usage reports from data collected on all the buildings on the campus. These reports are to show savings in energy when improvements or scheduling changes are made to a building.
Education
Master of Science - Electrical Engineering
University of California, Riverside
Riverside, CA06-2020
Bachelor of Science - Electrical Engineering
University of California, Riverside
Riverside, CA06-2019
Skills
- PROGRAMMING / SCRIPTING: Experienced with MATLAB, C, C, Python
- MACHINE LEARNING: Familiar with TensorFlow, Keras, Familiar with Neural Networks
- SOFTWARE TOOLS: Experienced with Visual Studio, Familiar SolidWorks, AutoCAD, Fusion 360
- SOFT SKILLS: Problem Solving: Strong analytical and problem-solving abilities, Collaboration: Ability to work effectively in cross-functional teams, Communication: Excellent verbal and written communication skills to explain complex technical concepts
Timeline
Speech R&D Engineer
Qualcomm
01.2025 - Current
Audio Systems Test Engineer
Qualcomm
05.2022 - 10.2024
Energy Management Data Analyst Intern
University of California, Riverside
08.2018 - 06.2020
Master of Science - Electrical Engineering
University of California, Riverside
Bachelor of Science - Electrical Engineering
University of California, Riverside