North Korea has lowered the volume of its border propaganda broadcasts at the inter-Korean Demilitarized Zone (DMZ) since Friday's Winter Olympics opening ceremony, a senior military official stationed at the border said Tuesday.

North and South Korea have been using large speakers to send a sonic barrage of music, news and propaganda at each other since early 2016, when the South restarted its broadcasts in retaliation to North Korea's fourth nuclear test that January.

"I still hear it, but it is much less than before," said the official who is stationed on the southern side of the border and spoke on condition of anonymity.

It was not immediately clear if South Korea had also turned down the volume of its broadcasts.

North Korean leader Kim Jong Un wants to boost the "warm climate of reconciliation and dialogue" with South Korea after his younger sister Kim Yo Jong led a three-day visit to the Games, North Korean state media said Tuesday.

The games are being held at the ski resort of Pyeongchang, about 80 km (50 miles) south of the border.

Mats Engman, a former major general who headed the Swedish delegation of the Neutral Nations Supervisory Committee in the DMZ until 2017, said any lowering or cessation of the broadcasts would be a small positive step toward dialogue.

Engman, who now works for the Stockholm-based Institute for Security and Development Policy, said the broadcasts had limited military value and could be irritating.

"When you live and work in the DMZ for longer periods and are exposed to an almost constant broadcast of propaganda, it may also negatively affect your judgment," he added.

"It can sometimes make it difficult for our officers to sleep, which in the long run makes people frustrated and irritated."