Audio & acoustic engineering portfolio

Practical tools.
Careful listening.

I work on signal-processing workflows for recording investigation, repeatable comparison reports, compact-model export and audio-driven motion timelines.

From the problem
to the deliverable.

Five case studies cover analysis work and implemented prototypes. Client recordings and source code remain confidential, so an original synthetic example in case 02 makes a comparison output inspectable.

01Audio restoration & investigationAnalysis & reportingReports: August 2026

Investigating noisy, low-bandwidth recordings

Four difficult recordings needed an assessment of background noise, discrete events and possible speech. I combined spectral analysis, classical processing and pretrained speech-enhancement models, then compared event and voice-activity diagnostics across the outputs.

Task
Examine events obscured by interference and limited bandwidth.
My role
Signal investigation, processing comparisons and preparation of the analysis reports.
Method
Welch spectra, short-time Fourier analysis, filtering, pretrained enhancement and cross-model comparison.
Output
Processed recordings and reports distinguishing candidate speech, tonal interference and unresolved events.
Evaluation
Compared spectral, event and voice-activity findings; no ground-truth transcript or measured intelligibility gain is established.
PythonDeepFilterNet3MetricGAN+SepFormerSilero VAD
What the analysis can establish

Enhancement can support listening and investigation. A voice-activity score does not certify words, speaker identity or recording authenticity, and enhancement models can introduce artefacts. Reports retain these limits rather than promise recovered speech.

02Recording comparisonAnalysis workflows & reportsReport rounds: 2024–2025

Repeatable analysis across recording conditions

Successive turntable accessory experiments needed a consistent reporting workflow. I developed tools to compare spectra, band energy, recording dynamics and channel relationships across test rounds. One combined report covered 156 recorded mat/clamp combinations.

Task
Compare many recorded conditions consistently and present their differences clearly.
My role
Analysis scripting, comparative figures and structured reporting across successive rounds.
Method
Batch analysis, frequency-band summaries, comparison plots and common reporting templates.
Output
Analysis scripts, comparison figures and reports, including the 156-combination report.
Evaluation
Recording-level comparisons; interpretation depends on acquisition controls, calibration and consistent metric definitions.

Recording differences alone do not establish a hardware-performance advantage.

NumPy / SciPypandaslibrosamatplotlib
03Compact acoustic classificationModel & export workflow

A small sound classifier with an embedded export path

An acoustic device project required a compact model to distinguish inhalation sounds from background noise. The project implementation uses 32 FFT-band features across eight frames and a 1,254-parameter convolutional network, followed by TensorFlow Lite conversion and C byte-array export.

Project scope
Feature preparation, offline classification and model-export artefacts for subsequent device integration.
Input & method
8 × 32 × 1 feature input; compact CNN training and representative-data quantisation/conversion.
Output & evaluation
Saved model, example-level evaluation and export artefacts prepared for a separate integration step.
  1. Represent the recording

    Arrange eight frames of 32 FFT-band features as the model input.

  2. Train and evaluate offline

    Use a compact 1,254-parameter convolutional classifier for the recorded examples.

  3. Convert the model

    Prepare representative data for the TensorFlow Lite quantisation/conversion workflow.

  4. Package the export

    Export a C byte array for subsequent device integration and testing.

Original explanation of the project workflow. Example-level results do not establish performance on independent users or devices. Target-hardware latency, memory and clinical performance require separate tests. Open the larger workflow schematic (SVG): compact classifier.
TensorFlow / KerasFFT featuresTensorFlow LiteC export
04Audio-driven motionOffline prototypeSaved documentation: September 2025

Turning game audio into a motion timeline

I built a modular, file-based workflow that extracts spectral and onset features, applies event rules and configurable motion mappings, then smooths and bounds the resulting signals before exporting a motion/vibration timeline.

Task & my role
Develop the offline processing modules, configuration presets and CSV-output workflow.
Method
Audio features and event rules → motion mapping → smoothing and configured bounds.
Output & evaluation
Python modules, presets and CSV timelines, with saved synthetic-example and output-schema checks.
  1. Load stereo audio

    Prepare a recording file for analysis.

  2. Extract spectral and onset features

    Measure energy, frequency-band cues and stereo balance.

  3. Apply event rules

    Identify transient and low-band cues for the configured mappings.

  4. Map events to motion parameters

    Generate pitch, roll, heave and vibration values using adjustable rules.

  5. Condition the signals

    Smooth the outputs and apply configured limits.

  6. Export a CSV timeline

    Write values on a 2 ms output grid for a subsequent integration step.

Original method explanation. The 2 ms spacing describes the output grid; it does not establish live processing at 500 Hz. Hardware integration and physical safety remain separate validation tasks. Open the larger workflow schematic (SVG): offline audio-to-haptics.
PythonlibrosaYAML configurationCSV tooling
05Audio DSPMATLAB / Simulink prototype

Classical denoising with an inspectable signal path

I developed a MATLAB/Simulink workflow to compare spectral subtraction and Wiener filtering through inspectable processing steps and before/after signal views.

Task & my role
Implement the classical filtering workflow and prepare signal comparisons for algorithm development.
Method & setup
Spectral subtraction and Wiener filtering. The saved Wiener demonstration uses a clean reference to initialise its noise estimate.
Output & evaluation
A MATLAB/Simulink model and saved signal outputs; no general intelligibility benchmark is established.

Applying the method to other recordings requires an appropriate noise estimate and a separate evaluation.

MATLABSimulinkSpectral subtractionWiener filtering

Signal analysis,
made usable.

Project approach

A clear question.
A useful result.

I scope the analysis around the decision or workflow the recording needs to support.

  1. Understand the recording and goal

    Define the input format, acquisition conditions, required outputs and criteria for a useful result.

  2. Build an inspectable baseline

    Start with signal diagnostics and a reproducible workflow; add models where they help answer the question.

  3. Deliver the workflow and its limits

    Agree the plots, data format and assumptions to report. Check reproducibility and output schemas against the task, then document limitations and next tests.

Have a recording
or a signal problem?

Start with the goal, input format and approximate duration or volume, acquisition conditions, required outputs and any target platform or deadline.

Please describe the task before sending any recordings; we can then agree the scope and how recordings will be shared and handled.

ahmadzafar577@gmail.com