Project by Philip Berrez and Alejandro Huertas
Abstract With people listening to music in public areas, there is a possibility of not being able to hear sounds that could prevent them from being hurt. This is amplified by the usage of noise-cancelling headphones, since they can remove the sounds from your surroundings, like the sounds of a car passing by.
We therefore tried to develop a system that could help people in similar situations.
A Bela board was used with a pair of earphones and an omnidirectional mic and the aim was to lower the music playing and send the input of the mic to the output when a loud noise was heard. At first the product was programmed in C++, but was exchanged for Pure Data, when it was discovered that C++ does not allow measurements of the amplitude from the mic.
The system was then tested at a crossing between Valhallavägen and Odengatan where there is a lot of traffic, and the threshold for triggering the mic was calibrated based on the testing done there. The results were 58 decibels as a threshold value at that crossing.