It is possible to modify the way the sound is configured?

During the introduction I can not hear what is being said because the volume of the special effects if louder than the volume of the speaking voice. Is there a way to lower the volume on the background noise, or raise the volume of the voice sound file?

Skip ahead to the selection screen and there will be a floppy disk icon. Click on that and you will have the option to enable subtitles for the speech and to adjust the sound effects and music volumes. Just click on them to cycle through the options. Those settings are retained after restarting the game. You should then be able to play the intro with the changed settings applied.