A few months ago, WhatsApp was working on a global voice message player. Now, it is reported that the feature is being rolled out in the latest beta.
According to WABetaInfo, the improved voice message player will allow you to listen to memos even when you switch to another chat. So if you're listening to a voice message from a friend and someone else sends you a message, you can switch to that other chat and reply to the person at the same time. What's changed since October is that WhatsApp was still working on this feature back then, while now some beta testers can try it out.
WhatsApp: The design of the player has also been changed
This requires version 22.1.72 of the app. WABetainfo points that some users are not yet able to try out this feature, as WhatsApp usually introduces new features slowly. In recent months, WhatsApp has also been refining the design of the player.

As you can see in the screenshot, the voice message is displayed at the top of the app with a play/pause button, the contact's name and a close button. Unfortunately, it is currently unknown when the feature will be made available to all users. (Photo by Denys Prykhodov / Bigstockphoto)