One child made a phone made with match boxes and thread. We began from there and together started pondering what all material can we use to make phone. What will happen with different thickness of thread and so on…
He made mobile with tin boxes, old pet bottles. I insisted to use cloth pieces also. Initially he was hesitant, later he tried and explained to me “cloth does not hold sound, so it will not work” He showed me that fabric weaving has holes while tin or plastic is compact.
By this time some more joined him and now they explored sound in a cone – some gave explanation about how sound expands, some stayed with theory that it contracts – I listened and enjoyed blowing the cone and listening my amplified voice through a cone :).