This week, we talked about the human auditory system in the lecture. The human hearing capacity can lie between 20 Hz and 20 kHz and we are able to recognize very faint sounds but also very loud ones, so there is a large dynamic range. Sounds are a result of mechanical vibrations travelling to a medium like air or water through compression and rarefaction. If there is a load sound, small muscles attached to ossicles in our ear contract which protects the ear. Since there is a delay in the response of these muscles of about 50-100 ms, there can still be damage if the loud noise is sudden. Sounds are transformed into neural impulses through the basilar membrane and the hair cells. Where a sound is coming from, the brain calculates through the time difference between a sound reaching first one ear and then the other. At the end of the lecture we also talked about some basics of audiovisual integration in the brain.
We also had our first excursion this week which took us to Elekta, a company that produces equipment and software to help cure people with cancer or brain disorders. First, we heard about the company’s background, how it was founded and how it developed to an internationally operating company. Then we were introduced to the MEG and EEG machines they produce which are used in many countries of the world, how the machines developed over the years and what they are currently working on, which is a machine that combines MRI and MEG. We were also told that they try to invent better solutions of cancelling out the noise in MEG data coming from movement of the head during the measurement. This was a good transition to the last speaker, who is researching in this exact field to especially get better results for measurements of children’s heads since, depending on what age, you cannot tell them to keep their head still for a long measurement.
I really liked that we got an insight in what they are currently working on, but I would have also loved to actually see some machines and how they are build. Unfortunately, their machines are built in a different place, so this was not possible.