So, you didn’t understand how to make it. Well, what am I here for then?
First step: install and run MS Talkit (download it from Downloads/AudioVideo).

Ok, now begin playing with it to acquire the method, then just reach the point, and do something like this:

So, after you tried Talkit and had fun with it, start Sound Recorder (Start > Programs > Accessories > Entertainment), locate it over Talkit, so when you switch from one another their windows don’t cover each other, and press in rapid sequence the Rec button in Sound Recorder, followed by the "Talk It!" button in Talkit. When the phrase is finished hit the Stop button in Recorder. Now, even if you’ve been a lot fast, there will be silent delays at the beginning and at the end of the WAV, so move the slider till you find a wave with a big amplitude,

then do [Edit > Delete before the current position] to remove the silence at the beginning. See when the Wave ends, and do [Edit > Delete after the current position], then do [File > Save] and go to mIRC’s folder (I suggest not going higher than 22KHz, 8bit, mono quality, it would be a waste of disk space; to achieve this, simply press the Change button in the Save dialog, and choose these settings).
Hewgh you did the same for allthe sounds you wanted to put in mIRC I hope (I mean Query, DCC Send, DCC Fail, DCC Complete, Notice, and so on), otherwise I just lost my time for a single 1.5 secs WAV file…
Now get back to the main mIRC Event Sounds page