DIY Sound Effects

by DIY Hacks and How Tos

Sound effects are the unsung heroes of movies, radio, and haunted houses. Hearing all the detailed sounds makes it feel the action is happening right next to you. By carefully selecting which sound effects are highlighted, you can create the perfect environment for your audience to experience.

In this project, I am going to give you a basic overview of the art of sound effects. I am going to show you how to make them, how to record them, and even how to automate them.

How to Make the Sound of Broken Glass

Another classic sound effect is breaking glass. The most common way to make this sound is to actually smash a pane of glass. But it is pretty inconvenient to contain and clean up a lot of broken glass. So here is a non-destructive alternative.

First, find a bunch of small glass objects of various sizes. I used glass vials. You want your glass objects to make different sounds. So I filled some of the vials with different amounts of water. Then find a bunch of small metal objects of various sizes. An assortment of small bolts and coins can work well. Again, you want the metal objects to make different sounds. Then take your collection of random objects and place them in a fabric bag.

Now gently drop the bag into your open hand or onto a pillow. You want to be very careful not to actually break the glass. Try this several different ways to see what makes the best sound. I got the best results when the bag rolled slightly after impact.

How to Make the Sound of Creaking Door and Floors

Two of the most iconic sound effects are creaking doors and wooden floors. There are a lot of ways that you can make these sounds. One example is a "creak box."

A creak box is a small wooden frame with a dowel going through the center. The dowel is held under pressure by a loop of rope and an eye bolt. When the dowel is turned, it rubs against the frame and makes a creaking sound. It works best if the rubbing surfaces are smooth and held tightly together. Turning the dowel slowly will make the slow loud creek of a door. Shorter quicker turns will make the creak of footsteps on an old wooden floor.

You can change the sound by adjusting the eye bolt. The position of the eye bolt sets the tension on the rope and the pressure on the dowel.

How to Make the Sound of Wind

Wind is another common sound effect. As with the other examples, there are a lot of ways to make this sound. My favorite method uses a bicycle and a windbreaker.

Turn your bicycle upside down. Then slowly turn the peddles with one hand and hold a piece of fabric up to the tire with the other hand. You can get different sounds by using different fabrics, by stretching the fabric, by changing the speed of the wheel or by using a bike tire with different treads.

How to Record Your Sound Effects

Once you know how to make the perfect sound effects, you need to record it. So the first thing that you need is a microphone. There are a lot of different kinds of microphones and each of them is best at a different task.

Once you have a microphone, the next thing that you need is a quiet place where you can record the sounds. Most people don't have access to a professional recording studio. So you are probably going to want to put something together in your house. This comes with a number of challenges. The biggest problem that you will have to solve is ambient noise. Most rooms are a lot noisier than you realize. Air conditioners, appliances, and nearby traffic make a lot of noise that can be picked up by your microphone. You could cover the walls in open cell foam in an attempt to make the room quieter. But the best solution is to build a pillow fort.

Surround yourself with pillows and loose blankets. A pillow fort is the probably the best DIY sound booth that you can make. It is free, it is easy to make, and it doesn't take up any permanent space. You can throw it together in minutes and take it down just as face.

How To Automatically Play Your Sounds With a Trigger

Sound effects don't need to be restricted to media like movies and radio. They can also be fun to use at live events. How would you like to have a fanfare play whenever someone walks into the party. Or maybe you would like to have a scary noise play whenever someone walks up to your house on Halloween. All you need to set this up is a simple microcontroller. There are a lot of systems that you can use to automatically play sound effects. An Arduino, a Raspberry Pi, and a Beaglebone can all be set up to play sound clips. But for a simple application like this, I decided to use a PicoBoo controller.

A PicoBoo controller is a record-playback system. Rather than coding the exact timing of each function, you program the controller by manually activating each function at the appropriate time. The controller is then able to play back this sequence whenever it is triggered by a sensor. These kinds of systems are common in theaters and haunted houses.

To use this system, first hook up your computer and speakers to the PicoBoo controller. Record up to two minutes of audio. Then hook up your trigger. This can be anything that connects the "IN" pin to the "GND" pin. You can use a switch, a pressure plate or even a motion sensor. Whenever the trigger is activated, the PicoBoo will play your sound effect.

How to Automatically Create Sound Effects Live

Automatically playing a clip of your sound effects can be really useful. But you can also set up a system to automatically create sound effects live. So why would you bother to setup the equipment to make sound effect live instead of just playing a sound clip? Well, a noise that is created right next to you has a fuller richer sound than something that is played out of a speaker. The sound of nails on a chalkboard is much more painful than a recording of the same sound. This technique is especially well suited for haunted houses and theaters.

Many sound effects can be automated using the same methods that you would use to make them in a recording studio. The only difference is that the human operator would be replaced by a motor. For example, you could use a motor to turn your creak box or your wind machine. A motor can also easily scrape two pieces of metal together or drag chains across the floor. Use your imagination. You would be amazed at how many different kinds of sounds you can automate.

Once you have figured out how to make your sounds with a motor, all you have to do is hook it up to a controller so that you can automate it. Once again there are a lot of microcontrollers that you can use, but for this example, I am using the PicoBoo controller.

Start by hooking up your motors to the output relays of the PicoBoo. To begin recording a sequence, press the "REC" button. Then press buttons 1 and 2 to activate the output relays at the desired time. To stop recording press the "REC" button again. To play back the sequence, press the 2 button. Once you are happy with how it is performing, then you can set up the trigger/switch. I hooked up a motion sensor to the "TRIGGER" pins. That way whenever someone walks into the room, the motors will automatically turn on and create the desired sound effects.

Enjoy the Art of Sound Effects

Creating sound effects is a fascinating and diverse art form. Sounds are all around us and you can use them to enhance just about any environment from movies and radio to live performances such as theaters and haunted houses. Try it out and have fun.

Content by Jason Poel Smith (DIY Hacks and How Tos). Used under Creative Commons 2.5 BY-NC-SA Licence. Changes were made to the original content.