Summary: Voice messages are delivered to your Gmail inbox, follow these instructions to listen to a voice message within Gmail.
To listen you your voice message within Gmail, open Gmail, then find and open the voice message. Voice messages will be delivered to your inbox with a subject line similar to the following:
Voice Message From: CALLERID NAME 1(847)123-4567
Attached to the email message you will be your voice message.
To play the voice message within Gmail, hover over the attachment, click the filename (the VoiceMessage[ID= part), and your voice message will play within the browser.
You also have the option to download the voice message attachment to your computer, or save the voice message attachment to Google Drive.
In both scenarios, the voice message will be saved as an MP3 file, with a filename similar to the following:
VoiceMessage[ID=4639896.000000 G=40 C=1 A=3BA9959E-6943-4D3B-9DA9-8E41D2FA036F R=0 F=300].MP3