Master Theses - Details

Spatially-selective Active Noise Cancellation for Headphones with Combined Active Acoustic Equalisation

Supervisor:  Jonas Förster, Florian Hilgemann

Area of Work: Signal Processing, Active Noise Cancellation, Acoustic Measurements, Filter Design

Category: Master Thesis

Status: Open

Keywords: Signal Processing, Active Noise Cancellation, Acoustic Measurements, Filter Design

Programming Language: Matlab

Tools: Matlab, Acoustic Measurements

Description

Headphones with integrated active noise cancellation (ANC) functionality became increasingly popular during the last decade as they can effectively attenuate unwanted noise. Besides, active hear-through established as an additional functionality. Thereby, surrounding sound is amplified in such way that the headphone appears as acoustically transparent. Both functionalities use the outer microphone of an ANC headphone and can only be used separately so far.

The use of additional outer microphones allows for using ANC and HT simultaneously. Hereby, we can, e.g., cancel unwanted noise from one direction while being able to perceive voices or work instructions from another direction by exploiting the spatial characteristics of the incoming sound.

In this work, an existing framework for spatially-selective ANC should be extended by a spatially-selective hear-through functionality. Therefore, directional transfer paths to the outer and inner microphones of a multi-microphone headphone prototype shall be measured. These can be used to evaluate the performance of the resulting framework by simulations. Based on that, it should be investigated whether the number of necessary outer microphones can be reduced while exceeding a certain performance value.

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