Ask Proxima does not provide noise ratings for the E1655U. However, it runs fairly quietly for a projector of this type in high brightness mode. In any event, its noise level is not likely to be an issue in almost any presenting environment you’d find the E1655U, and certainly not when presenting in the larger rooms that the E1655U's 5000 lumens allows. If a quieter environment is desired, dropping the E1655U into Eco lamp mode reduces the noise level to a very quiet level. If the aforementioned 24% drop in lumen output is acceptable, the E1655U would easily be quiet enough in Eco mode even in small venues. Basically, for a projector this bright that is intended to be permanently installed away from viewers, the noise level is not an issue.
The E1655U has a token built-in 7-watt speaker, which is enough to overcome the fan noise, but is not suitable for the larger scale venues where the E1655U is likely to be found.