One thing you should never underestimate is the power of manipulating normal sounds that are easy to record into different sound effects. Here are some examples to give you an idea:

Two screwdrivers tapped together and slowed right down so the pitch is low, make an excellent clank of someone climbing up a ladder. Vary the pitch as different rungs make different sounds.

A small creaking door window slowed right down can sound like a massive bulkhead, especially if you add some deep resonating echo.

A creaking metal gate slowed down, looped and crossfaded will sound like grinding machinery. Vary the pitch to control the speed of its action!

Traffic white noise put through a varying parametric filter will sound like a whistling wind.

From these examples it should be apparant that the most important thing to capture is a sample of the *texture* of the sound. Decide whether it should be plastic, wooden, metal, hard, soft, rattling, etc and record something similar. Get a large enough sample and then chop it up and use it how you want. Remember you can loop sounds to make them longer, alter their pitch or speed, change the volume attack to make it sharper or softer, crossfade sharp changes, mix in parts of other sounds... the possibilities are endless. The key is to get a good creative insight into how any complex sound might be synthesised using readily recordable domestic sounds.

Creating crowd effects is a particular challenge to an audio producer. Scenes which require the crowd to react to events may appear impossible to create without a real crowd at your disposal. Fortunately there are ways of cheating! The first thing you will need to assemble are a collection of crowd samples doing different things (ie. resting, cheering, booing etc.) You can either make these yourself with some friends, maybe multitracking one recording over another to multiply the number of people. Alternatively you could record some off the TV or radio, go on location and record a demonstration march or failing that buy a sound effects record.

The next thing to appreciate about crowd noise is that its random nature allows it to be easily looped and crossfaded. A quick tip for people working in stereo is that a mono recording of a crowd can be made convincingly stereo by delaying one channel by a few seconds against the other. Put, say, the left channel out of phase by 8 seconds and hear the recording come to life!

Once you have your looped samples, be they mono or stereo, you can easily layer them on top of each other and change the mood of the crowd by changing the volume of the relative recordings. Have for instance a basic level of background crowd noise and then you can fade in cheers or boos and mix the mood of the crowd appropriately. You be surprised how convincing this is. Because crowd noises are so random, your brain cannot pick out the mixed elements and accepts the impression of the sound as a whole.

Next we should look at making explosions. Most of these types of sound can be made from shaping white noise. The bang at the end of the Mobius Trap theme tune is an example of this. First get your sample of white noise or generate it with the white noise function on your wave editor. Next you should shape the amplitude envelope of the sound so that it is sharply loud at the beginnig and then tails off slowly. You can further enhance the bang by slowing it down so it is deeper, and applying a similar filter envelope to cut off the higher frequencies as the sound dies down. A gentle reverberation will also add character and warmth to the sound.

Laser gun sounds can be created in a similar way, only by using a pitched sound (diving usually) rather than white noise, and then experimenting by using flanger effects over the top to moke it "spacey".