[1] The sound was named by the 1906-1908 Denmark expedition after steamer Dijmphna, on which Danish Naval officer Andreas Peter Hovgaard attempted to reach and map the area to the north of the Taymyr Peninsula in 1882–1883, but ended up stuck in the Kara Sea pack ice.

[2] A polynya forms at the foot of the steep cliffs of Mallemuk Mountain so that there is sometimes open water in that area, even in the winter.

[3] The sound is structurally a fjord forming a channel that runs roughly westwards between the southern shore of Holm Land by Mallemuk Mountain to the north and Cape H. N. Andersen, at the NE end of Hovgaard Island to the south.

[4] Lynn Island is located about 30 km (19 mi) from the mouth of the Dijmphna Sound where it bends in a NE/SW direction.

Meanwhile, the sound bends further southward west of Hovgaard Island until it meets the Spalte Glacier flowing from the Nioghalvfjerd Fjord in the southwest.