Neural Activities Associated With Sounds of Different Frequencies

Abstract

This project aims to investigate human neural activity by listening to sounds of different frequencies. Brain of the subject was simulated by playing different frequency of sounds. An Electroencephalography (EEG) headset, Emotiv EPOC, is applied to record EEG signal on subjects for brain activity analysis.

Experiment was designed for and carried out with subjects. Frequency sound source was generated by functional generator. Each subject was required to listen to seven audible frequency sounds, i.e. 250Hz, 500Hz, 1 kHz, 2 kHz, 5 kHz, 10 kHz and 14 kHz. These sounds were played randomly, then the EEG signals from the brain activities were captured. Also, according to ISO226:2003 – a Normal equal-loudness level contour, the volume is controlled to prevent it being too loud or too high in power, which may cause uncomfortable and harmful feelings to subjects.

The next is to run pre-processing for the EEG recordings obtained from subjects. This conducted in EEGLab toolbox MATLAB. Artifacts and unexpected signals were removed by filters, linear rejection and Independent Component Analysis (ICA).

Finally, the desired recordings were transformed by Fourier Transform for spectrum analysis. This project’s outcome is to analyse the results and provide conclusion, by comparing neural activity associated with sounds of different frequencies.