I am located in the United States and have a natural gas (not LP) range in my kitchen fed by a natural gas utility.
Sometimes when I turn on my range, the appliance makes a whining or humming noise. This only occurs when gas is actually flowing:
If I adjust the burner on the stove top, the volume of the noise increases and decreases with the flow of natural gas. That is, on setting 2 it is quiet, on 6 it is very loud.
If I am using the oven, the noise only occurs when the oven burner is actually lit.
If I am using the broiler, the noise is constantly loud because the broiler burner is always on full blast.
No other NG appliances (clothes dryer, water heater, furnace) make this this noise.
At no time do I smell natural gas anywhere in my house. I have checked all flexible hose connections on each gas appliance and several black iron connections with soap and it appears there are no leaks.
This led me to believe it has something to do with the flow of gas specifically in the gas range. Google was helpful enough to point out a few useful links:
Based upon the problem description, the most likely cause is air and fuel ratios. Either to much air or to much fuel into the top burners. Which will create a hum, whistle or whining sound. Generically referred to as "noise."
Burner air ratio to fuel can be adjusted by slightly closing the air shutters on the burner tubes. One at a time close each shutter slightly and test. Flame must remain all blue. Listen to the burner while doing this adjustment. Noise should stop when properly adjusted.
Based on your symptom and details the gas pressure regulator is most likely causing the whining noise as the gas flow is being regulated. Replacing the gas pressure regulator will likely resolve the whining noise.
It appears my range has no user-serviceable components: I am not able to adjust "air shutters" or anything else on this model of range. This leads me to believe the most likely culprit is its gas regulator.
I do not want to replace or fix this range unless there is a reasonable risk that it will leak natural gas or some other issue that could cause damage to my house.
Given the evidence presented in this question, is there an elevated risk of my range malfunctioning in such a way that it will create a risk of fire, explosion, or anything else that might damage my house or its occupants?