Murmurs is something of a tidemark in audio drama, featuring as it does a number of more indie creators getting into the BBC space. Naturally I'm sure there's been a transition of people across the boundary previously, but I think this is the first concerted movement of a number of people.
It's an anthology series, of ten episodes with seven standalones and one set of three connected episodes, and can be thought of as an updated version of Appointment with Fear or The Man in Black. They're all relatively short tales, of 20-30 minutes, and mostly have a "sting in the tail", to steal a phrase. There are some hints that there's meant to be more connectedness in the overall arc, though that doesn't really come through.
I was rather surprised to find how much it used the conceit of telling the story through recorded media, eg phone calls, audio logs, radio transmissions etc. It's something of a common criticism of podcast drama that it feels the need to justify the sound existing, such as by someone making an audio diary that they happen to be uploading (often while something supernatural happens), and I'd expected this to play a bit more straight. It might simply be that the Beeb has decided to lean into this style at the moment as they continue to explore podcast space. (See their Lovecraft adaptations as a further example.)
But for whatever reason, that's the style, and it's used to tell a variety of tales. There's a time-traveling soldier, helping fix problems in a person's life. A girl who encounters "the witch in the top flat", and unlocks something inside herself. One of my favourites, about a fading librarian. Very few of them end well, mostly being horrible, or ambiguous at best. That very first episode is probably the most cheerful, so if you want a happy ending, leave that one till last. (There are some small elements that mean episode ten should be listened to last, but it's not really plot critical.)
That episode ten is part of the three episode arc, and it's one of the strongest parts of the show, likely because that additional time gives it room to lay out a proper arc and build a couple of different emotional peaks. It also has one of the strongest psychological horror elements in its first episode, that is delivered in a subtly creepy way but in general tapers off somewhat at the finish.
My favourite though is episode nine, "The Queue", written by the creators of Victoriocity, about a woman who can answer any question correctly. When you will die, where to meet your soulmate, though most people seem to prefer things on the order of "what are this week's lottery numbers?" or "what stock should I invest in to gain the largest possible return in a four year period?" And of course since she's always right, people are very keen to ask her questions, which results in a queue the size of a small town. What that means for society is given a quick explore, and it's that knock-on consideration that makes this one feel the most real.
Stylistically, they're fairly consistent, featuring archive clips of other, thematically related, programmes, as well as true silence scene transitions (akin to jump cuts) and the habit of censoring expletives with a neat glitch noise. It feels like a very spasmodic show, jumping around at a great pace and never content to sit for a moment. Did make me realise how much I miss The Man in Black though - would be nice to see this continue as an anthology show in that style. (Podcasts that might scratch that itch include: Night Terrors, Darkest Night, and The Magnus Archives.)