A stumbling block any new audio producer will encounter fairly early on will be the one of lacking sound effects. Unless you have several hundred pounds to buy your own professional effects library, you'll be left to make your own effects like the rest of us! This article will deal with creating a few common sound effects and hopefully give you an idea of how you can be creative with your own.

There are basically two ways to approach making a sound effect - You can either create it electronically or digitally with a synthesiser or sound effects program. Alternatively you can record a real sound live and then alter it to sound the way you want. Each approach has it uses and with time you will learn to judge when to use each. Sounds which are tonal or based purely on white noise are usually best done using a computer or synthesiser. Examples of these are sci-fi alarms and sirens, explosions, scanner sounds, blips and beeps, telephone tones, wind sounds, etc.

Sounds which are not so regular in form, ie. machinery clunking, footsteps, metallic sounds, creaking, rustling etc are better recorded live. First we will look at recreating all the sounds of a telephone, by way of example.

The first rule of recording "live" sound effects is that you should rarely bother recording the real thing. It's a curious paradox of the audio world that things never actually sound like what they really are when recorded. If you wanted, for instance, the sound of a lift door whirring open then you would most likely find a recording of a real lift door comes out as an indistinguishable metallic rattle rather than something the listener would immediately associate with a lift.

What the creative audio producer has to learn to do is to make sounds out of other sounds by chopping them up, altering their speed or pitch or adding processing effects. In the case of the lift door, you might find that a close-up recording of a sliding double glazing window, slowed down so the pitch is deeper, sounds far more like a lift than any real lift could!

Anyway, back to our telephone. Say we want the sound of the receiver being lifted followed by the sound of someone dialling, a ring and then an answering voice. To make the receiver sound we should be looking for something clunky and plastic we can rattle against a table. We settled for a portable tape-drive, but anything similar would do. We then noisily dropped the tape-drive onto a table from a few inches high, miking it up close. The result was perfect.

To make the dialling tones you can use the telephone tone function of Cool Edit. All you do is type in the number you want to dial and it makes up the tones for you. Next you need to cut out the tones and make the spacing between them more random, so it sounds like a human is dialling them not a machine. Once that is arranged you should run them through a mid-range bandpass filter to make the sounds tinny, as if heard down a phone line.

The final thing to do is to add the sounds of the buttons being pressed. Just record a key on your keyboard being pressed, or any similar tapping noise and paste the sound over the top of each of the tones. This will give the illusion of each key being pressed and making the tone.

Next we need to make a ringing sound. You could either use a recording of the real thing, by miking up your own telephone, or perhaps using the line in function of your modem to record the phone line direct, or alternatively make your own ringing sound using a synthesiser or even mimicking it by voice. Cut the ringing sound out and arrange it in a looped pattern that sounds like a phone ring down the line. Make sure also to add the same tinny bandpass effect that you added to the tone dials to give it that telephone feel!

Finally you should add a voice afterwards by cutting off the ringing abruptly, perhaps with a slight white noise click and then having the person at the other end of the line speak. Again run this voice through the tinny filter to give it the same effect.

For the final touches you might even consider creating some crackle to go on the phone line by chopping up and arranging ad hoc small snatches of white noise and clicks. And so there you go! One telephone sound effect.