These video clips are short and have been compressed as much as possible. Sound change relates only to the rod when stationary on the table or moving into the field of view, and there is a little sound caused by hand motion.
Sound presentation is monaural.
The sound pattern from the smooth cylinder is very different from that of the rough rectangular block. Stereo headphones really should be used here. Care must be taken to ensure that the left and right sounds are in the left and right ears. Many simple exercises have been completed before reaching this advanced level of understanding. In learning time, this may be between 5 and 20 hours.