Hello ElrodinCincy,
Thanks for posting. As I understand it, you have a question about listening to voicemail.
To clarify, when you play a voicemail, are you not hearing anything at all? Have you tried turning up your volume while the voicemail is playing? Adjust the volume on iPhone
Regarding speakerphone, when you start playing a voicemail, you should see a Speaker icon on the right (next to the blue phone icon and the red trash icon). Tapping that should play your voicemail through the speaker.
I hope that answers your question.
Take care.