buzz(ing), hubbub, din, hum
[noun]
[het ge-roe-ze-moes] 

‘Geroezemoes’ is the sound of a crowd of people talking but without it being distinct what is actually being said (like ‘buzz’ or ‘hum’). In Dutch one creates the noun that expresses the activity of a specific verb by taking the stem of the verb and preceding it with ‘ge’, e.g. for the verb ‘schreeuwen’ (to scream) the noun becomes ‘geschreeuw’ (screaming). In a similar way one can create the noun ‘geroezemoes’, however the verb ‘roezemoezen’ is hardly ever used (in my experience; I have actually never encountered it).

Although you may not encounter it often, the noun ‘geroezemoes’ is common vocabulary.

Examples:
– “Zullen we even naar buiten stappen, ik kan je niet verstaan door het geroezemoes.” 
(“Shall we step out for a minute, I can’t understand you over all the din hubbub.”)

– “Is de receptie al begonnen?”- “Ik geloof het wel, ik hoor flink wat geroezemoes aan het eind van de gang.” 
(“Has the reception started yet?” – “I believe so, I hear quite some buzzing at the end of the corridor.”)

– “Ik heb het idee dat geroezemoes altijd ongeveer hetzelfde klinkt, ongeacht de taal die gesproken wordt.” 
(“I have the perception that the hum of voices always sounds more or less the same, regardless of the language spoken.” Lit. “I have the idea that …”)

– “Nadat de directeur zijn toespraak beëindigde, klonk er direct geroezemoes op uit de zaal.” 
(“After the (managing) director ended his speech the crowd in the room/hall buzzed immediately.” Lit. “buzzing sounded out of the room/hall”. A ‘zaal’ is a big room/hall.)

– “Het geroezemoes in de kamer hield direct op toen de spreker zachtjes tegen zijn glas tikte.” 
(“The hum of voices in the room stopped immediately when the speaker gently tapped his glass.”)

Related words:
– Roezemoezen: to buzz, bustle, hum [verb] [roezemoesde, geroezemoesd].
– Mompelen: to mumble [verb] [mompelde, gemompeld].
– Achtergrondgeruis: background noise [noun] [het geruis, <no plural>].