This is simply done by adding the following code while in HTML mode of your blog composer:
<embed width="250" height="50" autostart="false" loop="false" playcount="2" src="http://YOUR-PERSONAL-SOUNDFILE.wav" span title="YOUR OWN TEXT"></embed>
That's it, you are all set, ENJOY!
Note: Blogger is very fussy with some codes, such as this one. Once you are done editing this in HTML mode you will notice that upon going to compose mode and than back to HTML mode your wav will disappear.