Residents near Rotterdam’s Euromast reported a persistent whistling or high-pitched noise since June, saying it had disrupted their sleep and worsened in autumn. Hundreds of complaints were submitted to the DCMR environmental service, the municipality and the tower, including at least 75 during one week.

DCMR determined earlier in October that the Euromast was the source of the tone, while a later report said the service had traced it to the tower’s upper section but had not yet identified its cause. An initial theory involving loose cables was ruled out after a contractor tightened them and the noise continued following the tower’s July reopening. A specialist engineering firm is now assisting the investigation. DCMR cannot exclude that some reported noise has another cause and that the Euromast is not the sole source of all nuisance reports.