One could, presumably, listen to the Dragnet radio show in the shower back in the 1950’s. Recently I listened to Dragnet while taking a shower. So, has nothing changed? Well now… let’s look things over.
The 1950’s version would have meant a radio (AM, tubes) or at least a speaker, connected to such a radio, in the bathroom – an unlikely, but not impossible, thing in that time.
In 2018 (and 2017, for that matter, and likely for some years earlier for others) the signal didn’t start at a big radio network, but some smaller server. In this case, whoever hosts “Hank’s Gumshoe OTR” (OTR: Old Time Radio). That gets distributed over the internet, and when the connections are all set up, it arrives at the Labyrinth via cable. From the cable it goes to UHF (WiFi) and thus to a smartphone. The phone runs an internet radio application and plays the show currently broadcast. But the phone has no water resistance rating (one of the few downsides of the particular model) thus is kept away from the shower, and so the audio is flipped to a portable water-resistant speaker via Bluetooth (UHF again).
The radio show hadn’t changed, save perhaps for surface noise from the transcription disks, since the original airing. The technology to hear it sure has, though. It went from an all analog setup with AM broadcast, to digital distribution where analog is an output.
 While it could have been a transistor radio, realize those were expensive and uncommon for a while – and didn’t show up until about the mid-1950’s.