They were wrong.
The microphones revealed that bowhead whales traveling through the area sang nearly constantly - day and night - for around 5 months in the winter. More than 60 unique songs were recorded. You can read about them in a feature article in Endangered Species Research.
"We hoped to record a few little grunts and moans," Stafford was quoted as saying in the press release. "We were not expecting to get five months of straight singing."
The researchers aren't clear on what this means, in terms of that area's bowhead whale population. In most other kinds of whales, she explained, individuals either sing the same song their whole lives or all members of a population sing the season's same popular tune.
If bowheads are like the former, that would mean more than 60 males were in the Fram Strait. If the population is evenly split between males and females, there could have been more than 100 whales, far more than anyone thought was in this population.
I hope the whale population there is rebounding!