Timos Papadopoulos

Identification of auditory cues utilized in human echolocation - objective measurement results

We present objective measurements of source-to-ear responses obtained in a previously established human echolocation experimental paradigm. We identify the auditory cues that allow humans to perform echolocation tasks in that specific scenario and we discuss the salience of those cues with respect to more complex scenarios. This work allows us to formulate an experimental protocol for conducting more detailed and informative subjective listening test experiments in human echolocation.

Determining the Binaural Signals in Bat Echolocation

Echolocating bats are known to outperform manmade systems in the tasks of autonomous navigation and object detection and classification, especially when size, power and computational complexity requirements are considered. As a result, the individual physical mechanisms and processes involved in echolocation (types of signals used, properties of the emission mechanism, echoes created in different echolocation tasks, receptor characteristics as well as the bat’s auditory system) have received significant attention as a possible source of bio-inspiration. However, not much attention has been drawn to optimisations that may arise as a combined effect of the above mechanisms. Of key importance in such an investigation would be the knowledge of the binaural signals generated in real echolocation tasks as those are the actual input signals utilised by the bat’s auditory system. The direct measurement of these signals is severely restricted by the very small size of most bat species. We describe the development of an experimental facility that combines the measurement and modelling of the aforementioned subsystems for the determination of the binaural signals associated with echolocation. We present initial measurement results and compare them with analytical modelling predictions

Organising, providing and evaluating technical training for early career researchers: a case study

This paper considers the importance of providing technical training opportunities for Early Career Researchers (ECRs) worldwide through the case study of a MATLAB training programme, which was proposed, organised, managed and evaluated by a team of five ECRs at the University of Southampton. The effectiveness of the programme in terms of the improvement in technical competency and the encouragement of interdisciplinary collaboration between the ECRs receiving this training was evaluated using measures relating to levels 1 (Reaction), 2 (Learning) and 3 (Behaviour) of the Rugby Team Impact Framework evaluation model. Overall reaction to the training course was extremely positive and data from pre- and post-course surveys suggest a positive change in the long-term behaviour of delegates. The ECRs who organised this project gained valuable experience in team working, grant writing, project management and the development of teaching materials. Details of the organisation and evaluation of the course are presented.

Modelling of the echo generation process in bat echolocation

Very few studies exist that attempt to model the detailed shape of the echoes generated by real targets in bat echolocation. The modelling becomes even more complicated when one attempts to take into account the specific acoustic characteristics of the bat as a source and receiver. Hence, the exact physical acoustics basis that underpins the target detection and classification capabilities demonstrated by bats remains a largely open research question. We use previously published work on real target echo measurement (Simmons and Chen, JASA 1989) as a starting point but modify their experimental method in a way that allows the incorporation of the bats source and receiver characteristics in the modelling. Furthermore, we compare our measurements with analytically predicted results and show good agreement. We discuss how our experimental method can be used for the prediction of the binaural signals that constitute the actual input to the bats auditory system during echolocation.