Solution: Have all voicemails automatically emailed to you as sound files. This also ensures you are notified quickly when any new voicemails are left. Spectrum Business Voice offers this as a free service to its customers. Voice messages are attached to the emails as mp3 sound files, and recipients simply click on the email attachment to start listening.
Share with your caller when they can expect a callback. If you return calls within 24 hours, let them know. Give them an estimate of when they can expect your call.

You can play a voice message at different speeds and pause/resume the message, using desktop client visual voicemail, or by dialing into their voicemail. Pressing a certain key on your phone controls how you can hear the voicemail: Read your voicemail transcription
I have a confession to make: I haven’t recorded a new voicemail greeting since 2014. In the past four years, I (hopefully) have become more articulate, poised, and self-assured. But hear my voicemail recording, and you’d think I was still new to the work world, a little unsure of myself — and probably not an authority. Obviously I need toupdate it. And if you haven’t changed your voicemail greeting in over a year, you’re likely in the same boat. After all, a professional voicemail recording boosts your credibility, makes you seem more competent, and encourages whoever’s listening to it to continue the relationship. A relatively unprofessional one — like mine, for instance — does the opposite: It encourages prospects, recruiters, and potential connections to run in the other direction. With that in mind, I’ve written 18 unique voicemail greetings for every situation. Pick your favorite, practice a few times, then record your new voicemail.