This post is great as an introduction to how effects change audio. There are 17 different types of effect described in this article and there is an audio example of each one.
The audio treacks are played via podsnack.com – a great site of embedding audio into your blog or website. Right click the audio web llink and choose “open link in new tab” for a better experience.
Have fun!
For Audio Sound Effects, use this website. It works in school only as it is free for teachers and pupils. Click here for Audio Sound effects.