I’d bet good money that most voicemails never get played. Instead, they just sit there serving as extra “missed call” notifications, letting you know to call or text back whoever bothered to leave you the message in the first place.
And if you find that you mute your phone accidentally, you need to unmute it then you can hear the sound. 1. For iPhone users, they can go to check whether the Ring/Silent switch is turned on. If the switch shows orange, that means your phone is in the silent mode so you need to toggle the button to turn on the Ring mode.

If you can't set up Visual Voicemail, contact your carrier to make sure that your plan supports the feature.
To get the most out of your voice mail it’s important that you properly set up your personal mailbox. Press the voice mail button on your phone and enter your password (0 0 0 0 by default). Press 5 from the mailbox menu. Press 1 to assign your no answer greeting Press 2 to edit the greeting, begin recording when prompted. A typical greeting says “Hi, you’ve reached Mitch Scott. I am currently on the other line or away from my desk. Please leave your name number and a brief message and I will return your call as soon as possible.” press # when finished. Press 1 to set this as your active greeting Press 5 to edit mailbox greetings Press 7 to record your mailbox greeting and follow the prompts to record your mailbox greeting (You can repeat the greeting you used in step 3). Press # when finished. Press # from the main menu Press 7 for personal administration Press 2 to record your name “Mitch Scott” press # when finished Press # from the main menu Press 7 for personal administration Press 3 to enter your directory name Press 2 and follow the instructions to enter your name in the directory Press # from the main menu press 7 for personal administration Press 1 to change your password Press 2 and follow the instructions to change your password.