Sunday, July 07, 2019

The talking brick mix

Melbourne train users have been used to 'talking bricks' for decades. Most have two buttons. Red for emergencies and green for the next three trains. They are at all stations on the electrified network and are a substitute for visual passenger information displays (becoming more common but still missing from some smaller stations).

They are not marked as being suitable for use with hearing induction loops. Their metal box likely shields the electromagnetic field from the speaker. However if you hold a sensitive enough induction loop near enough to the speaker you can detect announcements.

I took advantage of this to record automated announcements. I then made multiple copies (about 15 or 20), moved them around and varied their volume. The video below demonstrates how it came out.

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