If you have a machine equipped with a built-in speaker or an attached speaker, you can listen to the audio file by doing the following:
Open Mail Tool.
Double-click SELECT on the message header containing the attached audio file in the Mail Tool base window.
The mail message containing the file is displayed in the View Message window.
Double-click SELECT on the audio attachment glyph in the view window Attachments area.
The audio file opens and begins playing.