I thought I would share with you some sound level measurements I have taken in my quiet basement lab over the years.
Please note the levels have not been obtained with a calibrated instrument, so the absolute levels are rather worthless. But I have been careful to always use the same device (an old iPhone 4 I keep only for this purpose), running the same software (SPLnFFT), while positioned in the exact same spot and orientation, so RELATIVE levels should be meaningful.
All measurements are db(A).
Room background with everything turned off : 28.0
mac mini 2018 running at low load : 29.7
HP Z820 workstation idling with fans set to lowest speed : 36-39
Logic Analyzers :
HP 1663C : 39.5
HP 1670G : 48.2
HP 16700A : 52.2
HP 16700A refitted with Noctua high static pressure fans :42.5 peak, 40.0 idle
Oscilloscopes :
Tektronix 2213: high pitched whine, otherwise silent
Tektronix 2265 (original model with auto fan speed) : 37.5
Tektronix TDS744A : 43.2
Rigol DS2072A : 38.0
Rohde & Schwarz RTC1002 : 29.8
Others :
HP 5345A counter : 56.0 (a real monster this one!)
Siglent SDG 2042X ARB : 31.4
Obviously the fanless instruments are normaly silent. It's why I prefer my old brown Keithley DMMs to newer models.
The siglent 2042X dominates the soundscape when just the mac is running while the RTC1002 I cannot detect, so a difference of 1.5 db is clearly audible.
What are your experiences soundwise with your gear? Is your lab quiet or noisy?