There are various types of noises that are produced by the steam generator:
1) Noise from the stand
This is characterized by a vibrating sound that happens at irregular intervals or every time steam trigger is pressed.
The noise is related to water being sent from the water tank to the steam generator. This is normal. Filling the water tank helps alleviate the issue.
However, you can reduce the noise by not placing the steam generator on a hard surface. You may also put a piece of soft material, e.g., a cloth under the steam generator.
(Models with detachable water tank) This may also be caused by the water tank having not been fitted properly. After letting the iron cool down for at least 2 hours, take the watertank out and put it back in again, checking if everything sets in properly.
2) Noise from the iron
This is characterized by the whooshing sound that can be heard when steam comes out of the soleplate.
This is normal for steam generator with high pressure steam.
(Models with ECO setting) You can reduce steam by selecting a low steam or ECO setting.