Make a DIY Air Horn

Materials you'll need

• Long plastic tube (like PVC pipe)
• Short plastic tube (a small PVC coupler or connector)
• Balloon
• Electrical tape

 

Step-by-step tutorial

Step 1: Gather your two plastic tubes — a long one to blow through and hold, and a short coupler piece.

Step 2: Stretch the neck of the balloon open and slide the short tube inside it so it sits just inside the balloon's neck opening.

Step 3: Slide the balloon (with the short tube inside the neck) onto one end of the long tube, so the balloon neck wraps around the end of the long tube.

Step 4: Pull the short tube over the end of the long tube so the balloon neck is squeezed snugly between the two tubes. Wrap electrical tape tightly around the joint to hold everything in place and seal the connection.

Step 5: Put your mouth on the open end of the long tube and blow to inflate the balloon. 

Learn more

When the balloon deflates, air rushes through the tight gap where the latex neck meets the tube. That squeeze makes the rubber vibrate rapidly — the same way your vocal cords vibrate when you speak. Those vibrations spread through the tube and out into the air as sound waves you can hear. The long tube acts like the bell of a trumpet, helping amplify and project the sound. Changing how tight the latex opening is changes how fast it vibrates, which changes the pitch and that's how you control the honk.