Expert Lecture on

Array Signal Processing for Acoustic & Brain Source Localization

23rd September 2024

IEEE Student Chapter, Dronacharya Group of Institutions, Greater Noida organized an expert lecture on “Array Signal Processing for Acoustic & Brain Source Localization” on 23^rd September 2024 for ECE/EEE/ECZ department students.  Dr. Lalan Kumar (Associate Professor in the Department of Electrical Engineering of IIT Delhi,) was invited as a guest speaker.

The primary objective of the session was to familiarize the audience with the wide range of Array signal processing.

Prof. (Dr.) Arpita Gupta, Director of DGI, felicitated Dr. Lalan Kumar and provided a brief introduction about his achievements and contributions. She then handed over the dice to Dr. Kumar, inviting him to continue with the session.

Dr. Kumar explained ASP is a powerful technique used to determine the direction and location of sound or brain activity sources. The method involves using a collection of sensors (or microphones) arranged in a specific pattern to capture the signals from the source.

During the session discussion was made about on Acoustic source localization. It is a technique used in audio engineering, robotics, and surveillance to determine the location of a sound source in a given environment. Common methods include time-of-arrival (TOA), time-difference-of-arrival (TDOA), frequency-domain methods and beam forming, which use different methods to calculate the source's location.

 He then explained common methods for acoustic source localization. The method includes

• Time-of-arrival (TOA):Measures the difference in arrival time of the sound signal at different microphones to calculate the source's location.
• Time-difference-of-arrival (TDOA):Similar to TOA, but uses the difference in arrival time between pairs of microphones.
• Frequency-domain methods:Analyze the frequency content of the sound signal to determine the direction of arrival.
• Beam forming:Creates a virtual beam that steers towards the source, allowing for localization based on the beam's output.

Moving the session further Mr. Kumar explained Brain Source Localization It aims to identify the location of neural activity within the brain. This technique is used in various neuroscience and medical applications, such as:Electroencephalography (EEG): Records electrical activity on the scalp to localize brain sources. Magnetoencephalography (MEG): Measures magnetic fields produced by electrical activity in the brain.Functional magnetic resonance imaging (fMRI): Detects changes in blood flow related to neural activity.

 Some of the common methods for brain source localization include: Dipole localization, Beam forming, Independent component analysis (ICA), Bayesian methods  

Mr. Kumar also then discussed challenges and considerations. These include

• Noise and interference:Environmental noise and interference can degrade the accuracy of localization.
• Multiple sources:When multiple sources are present, it can be challenging to distinguish and localize each individual source.
• Sensor calibration:Accurate calibration of sensors is essential for reliable localization results.
• Computational complexity:Some methods, especially those involving complex models or iterative algorithms, can be computationally intensive.

 In the last Advancements and Future Directions was discussed by Mr. Kumar which includes:

• Machine learning:Machine learning techniques are being explored to improve localization accuracy and efficiency.
• Multi-modal approaches:Combining data from multiple modalities (e.g., EEG, MEG) can provide more comprehensive information about brain activity.
• Wireless sensor networks:Advances in wireless technology are enabling the development of flexible and scalable sensor networks for localization applications.

Finally, session was concluded by giving the vote of thanks by Prof. Sanghamitra V. Arora,( HOD-ECE, EEE, ECZ of DGI). 

Overall the session was fruitful and praised by all the students as well as faculty members for engaging and enthusiastic presentation, with several research opportunities.