Once the application has loaded and you have correctly installed and set up the microphone, build your ppt and create the text around which you want to add the sound files.

In this example we are going to embed the sound file directly into the slide. This works well if each sound file is no larger than 100k (so not really a lot of file size to play with) Possibly 30 seconds or so.

Click 'insert' and a sub menu appears

Open up the sub-menu

scroll down carefully and choose 'movies and sounds'

and then 'Record Sound'

A small window appears asking for a file name - you can give this any name that you want. Keep each sound file name different to the last. eg sound_001 , sound_002 etc.

This is important, because if you exceed the 100k limit that the embed can easily cope with, Powerpoint will create a small attached file with the name that you chose to reference the sound and the page. And...if you do exceed this 100k limit, the file will then need to be carried along with the final powerpoint show. Rather like webpages ref images and other media online.
But for now we can just try some short examples.

When you are ready, and close to the mic, click the red 'record' button and off you go.

Once you have finished, simply click the square 'stop' command.

You can review your recording before you put it on the page by clicking the 'play' triangle

Once you are happy and have clicked 'OK', a small speaker icon appears on the slide with the option of 'play when clicked' or 'play automatically'

You can select either depending on how much control you want to give the viewer.

The icon can be moved anywhere around the page, resized etc. Designers might encourage you to keep the icons small and unobtrusive.

It's that simple

But remember if you have other attached sound files to the slideshow, they will be 'dead' if you subsequently move your slide show presentaion to another location and leave as orphans the files needed by ppt.

Just keep everything altogether, you can also zip up the show with the related files using 'winzip'. The zipped file will then contain everything needed for anyone else to watch the presentation