sound science experiment

This science experiment and lesson in how sound travels will help kids understand why the Holy Spirit is an equally special member of the Trinity. If you’ve used St. Patrick’s shamrock to teach the Trinity, it’s a great new way to show the power of three!


• Tubes (from a power-towel or gift-wrap roll), one for each pair of students in your class
• Cones made out of construction paper with a fairly wide mouth, one for each pair of students in your class


We’re going to do a science experiment to see how sound travels – and to understand how that relates to the Holy Spirit. St. Patrick is most famous for teaching about the Trinity — Father, Son, and Holy Spirit — using a shamrock. Using sound to understand is also great fun!


  1. Form the class into pairs, and give each a tube and a cone.
  2. Have partners take turns speaking into each other’s ears with each item.
  3. What are the differences?


Sound travels in waves. They also bounce off of solids such as the tube and the cone. Through the tube, the sound is coming almost straightforward in a way that is more closely contained by solids. It sounds strong, but also muffled, because the higher sound waves are bouncing off the solids at their high frequency, making them into lower frequency.

Frequency is the rate at which a vibration occurs, which constitutes a sound wave. Higher sounds come from higher frequency and higher sound waves. When the high sound waves bounce off the solid, they slow down and become lower, sounding muffled.

When hearing through a cone, the solid sides are not nearly so confining. If you are standing next to the cone, the sound will be almost identical to what you would hear without it. But the cone also “shoots” sound outward so that it carries farther. That’s how megaphones got to be popular in crowds such as sporting events.

Understanding God

People often say they have trouble relating the God of the Old Testament to the Jesus of the New Testament and to the Holy Spirit of the church. The God of the Old Testament seemed harsher and less loving, they say. God is very loving, and that is obvious in the Old Testament to anyone who wants to see it. All his harshness had to do with love and was in response to the bad behavior or hatred which he was then forced to address.

But it becomes much easier to see with Jesus, who became famous for saying things like “Love your enemies, and pray for those who persecute you.” (Matthew 5:44)

God and Jesus are like the tube. When we pray, it is a little hard to hear them, though we may feel strong impressions in our hearts. Those impressions are like the volume when listening through a tube, and the muffled high sounds are like trying to understand his will.

Turning the tube into a cone provides for much clearer hearing and much longer distances for that sound to travel. The Holy Spirit becomes part of your life when you receive Jesus into your heart. You are then surrounded by the Holy Spirit, whom Jesus called a counselor and comforter. The Holy Spirit makes God’s will clearer in our hearts!