Radio is an important propaganda tool for North Korea. As North Korean defector Park Young-mi explains:

Almost every morning, we all woke up in a nation that resonated with government-supplied radio. The radio met every household in North Korea and was not allowed to switch off.
The channels were always tuned to the only state-run broadcast, and the government controlled the people while at home.
In the morning, a series of courageous songs entitled “The Prosperous Powerful Country” reminded us of our fortune to live as a proud socialist. “(Pak Yong-mi,” The Choice to Live “)
Collaborative work has been a way for us to maintain a revolutionary spirit and unite the people. We always had to do everything at the same time.
So when the radio starts at noon, everyone stops eating lunch at the same time. There was no escape from it (ibid.)

According to North Korean defector Kang Hyuk, the broadcast on the radio will be Pyongyang Broadcasting.

At our house, like other homes, there were speakers who broadcast Pyongyang programs. From it came the news of the beloved leader Comrade Kim Jong Il and the songs dedicated to him or made in honor of his father’s glory. In some homes, the speakers were no longer painful, but in my home they weren’t so well-maintained. There was a radio in my house and I could listen to Pyongyang Broadcasting. (Kang Hyuk, Children of North Korea)

Radios owned by residents are subject to regular unannounced inspections.

Police sometimes perform unannounced inspections of all registered receivers. Managing the correct specifications of the radio is an important task of the so-called People’s Group, the leader of the People’s Group.
At any time (even at midnight), the head of the People’s Team can enter to check for unregistered receivers at any time. In recent years, the number of freely tunable radios brought in from China has greatly increased. Such radios are widely used to listen to Korean broadcasts. (Andrey Lankov, North of the DMZ: Essays on Daily Life in North Korea)

Refer to the article  What is the “Inminban” for the People’s Group.

In North Korea, besides receivers distributed to households, there are also cable radios broadcast from street speakers.

5:00 am every morning. On North Korea, “Third Broadcasting”, a nationwide network of wired radio, begins broadcasting. An important advantage of wired radio is its ability to target only certain areas. Widely used by North Korean civil defense systems during air defense exercises.
“Third Broadcasting” plays an important role in hosting various public events. Directives are issued to local residents through wired radio speakers. You will be instructed when and where to go, in what dress, and what to do to welcome the foreign delegation.
When foreign guests have the opportunity to talk to local residents, North Koreans are given clear instructions on how to answer the questions most likely to be foreigners. Since the 1980s, new apartments have been obliged to install “wired radios”. Speakers are in offices as well as homes. “Wired radios” are often connected to large speakers installed in public places.
A constant army march, sometimes interrupted by news.
“Third broadcast” programs consist of a combination of music, news, and educational programs, and all have a strong advertising odor. On the other hand, there is a lot of short news and music during the day. In the past, music consisted only of military marches, but now North Korean versions of the pop are often played. In the evening, there is a continuous “radio drama” and a novel reading. Despite the dark ideology, North Koreans like the Third Broadcast. In many homes, the “third broadcast” is the only source of entertainment. (Ibid.)