Amplifying Sound

Theme: God gifted us with an impressive and complex hearing system.

Bible Verse: I will praise You, for I am fearfully and wonderfully made; marvelous are Your works, and that my soul knows very well. (Psalm 139:14)

Materials Needed:

• Sheets of paper

• Tape

• Straight pins

• Fine-grain sandpaper

Bible Lesson

David was deeply impressed by the creation of life, as each of us should be. In our day, however, ideas contrary to creation abound, such as evolutionary origin and slow improvement through random mutations. David’s testimony is a refreshing and timely contrast to such false ideas.

As just one example of creative design, consider our sense of hearing. Our ears allow us to enjoy birds and musical instruments, voices and songs. Hearing also protects us by warning of approaching danger.

The assumed evolution of the ear has not been explained in detail. Somehow our animal ancestors are said to have developed open canals beneath their skin, along with cells sensitive to sound vibrations. But consider the complex sequence of vibrations that must work together perfectly when one hears a sound. The sequence of sound vibrations moves through each of these objects in turn:

Violin string

Air molecules

Outer eardrum

Hammer, anvil, stirrup (the three smallest bones in our bodies)

Inner eardrum

Fluid within the ear’s cochlea

Hair follicles lining the cochlea

Electrons within nerves at the base of the follicles

The brain circuitry itself

When the vibrating electric signal finally reaches the brain, we hear beautiful music. All this happens in a split second, and with vibrations of hundreds or thousands of cycles per second.

How could such a complex system evolve over time and completely by chance? All the details of the ear must be present and working together for hearing to exist; the ear simply could not develop haphazardly or slowly. Similar examples of God’s intricate design can be seen throughout our bodies and the entire creation. Evolutionary alternatives to David’s testimony are neither convincing nor scientifically satisfying.

Science Activity

This activity explores the definition of sound as a vibration. A simple sound amplifier can be made with a sheet of paper and a straight pin. Roll the paper into a cone and tape it. An opening is not necessary at the tip; uneven paper at the flared end does not matter. Now reach inside and push the pin through the narrow end so the pin point protrudes outward to the side (not through the tip).

Hold the cone and pull the pin across any object; it will vibrate and the paper megaphone should amplify the sound. Try rubbing the pin across cloth, sandpaper, or any other rough surface. A static sound will result as the pin vibrates unevenly.

A homemade paper loudspeaker will amplify sound.

Science Explanation

Sound can be defined as a vibration, whether caused by a violin string, a drum, or a person’s vocal cords. In this experiment the pin vibrates rapidly by passing over a rough surface. The paper cone attached to the pin also vibrates. The greater size of the cone then causes nearby air molecules to vibrate. This air pressure disturbance finally reaches our eardrums. The cone is somewhat similar to an audio speaker inside a radio or television.