September 2020, the first ship was ESI noise certified. On the website of DW-ShipConsult, (https://www.dw-sc.de/en/aktuelle/) the following message was published.
The ESI-Noise certificate is based on the results of a comprehensive noise measurement by DW-ShipConsult. The measurement took place in the Port of Hamburg and followed the official NEPTUNES measurement protocol. According to this protocol, relevant noise sources on board like exhaust gas outlet or ventilation fans are measured directly. Also, noise measurements at given receiver locations are considered. A calculation process summarizes all measurements and considers annoying effects like low-frequency tones. The resulting noise index (ESI-Noise) can be used to apply for port fee discounts in Rotterdam, Hamburg, or other ports”.