Project Description

Experience the interplay of sound and space with this interactive simulation designed to demystify the comb filtering phenomenon in multi-microphone environments. This project explores how slight differences in distance and orientation between a sound source and multiple microphones can lead to phase cancellations—producing a distinctive “comb” pattern in the frequency response.

Overview

Developed during the Spring Term at the German University in Cairo as part of an Audio and Acoustics course, the simulation enables users to drag a sound source and multiple microphones around a virtual canvas. As positions are adjusted, the program recalculates the distances and delays between the source and each microphone. The output consists of a dynamic plot of the comb filter effect versus frequency (up to 20 kHz) and a real-time display of null frequencies. The simulation supports two operating modes: one that factors in the natural decay of sound with increasing distance, and another that visualizes the effect without decay.

Development Process

The project combined theory with hands-on programming to create a user-driven experience:

• Interactive Environment:
  Using a Python-based interface (built with tkinter), a cyan canvas was set up where the sound source and microphones could be freely moved. This draggable setup allowed for real-time updates on positions, distances, and the resulting audio delays.

• Signal Analysis & Visualization:
  Upon repositioning, the application calculates the time delays induced by the varying distances, shifts the audio signal’s time axis accordingly, and displays a frequency spectrum for each stereo channel. Dynamic plots illustrate the comb filter effect while listing the null frequencies that occur in the audible range.

• Simulation Modes:
  Two distinct modes were implemented—one that considers the natural decay of sound intensity with distance and another that presents the raw comb filtering effect without attenuation. This feature lets users clearly observe the impact of sound decay on the perceived filtering effect.

• Collaborative Development:
  The project was a team effort, with clear delineation of roles: one member focused on the draggable object functionality and the underlying distance and delay calculations, while the other handled the amplitude to dB conversion and the decay mode implementation. This collaboration ensured a robust and well-rounded simulation.

Results & Impact

The final output is a set of visually engaging and educational tools that not only demystify the comb filtering phenomenon but also provide quantitative insights into the effects of spatial arrangement on audio quality. Users can watch the dynamic changes in the frequency spectrum and gain a clear understanding of how multi-microphone setups interact to produce phase cancellations.

What I Gained

Working on this project deepened my understanding of acoustic signal processing and advanced digital simulation techniques. I honed my skills in interactive interface design, real-time data visualization, and the practical application of theoretical audio principles. This simulation stands as a compelling demonstration of how everyday phenomena in audio engineering can be explored and understood through innovative computational tools.