Why not look in the consumer mag on the topic. Your library should have free access if you are not a member. 

Consumer NZ has just today released their latest test of electric jugs and kettles.  Top of the list is the one we had just bought a couple of weeks before, the Russell Hobbs Montana RHK142.  It really is quiet, despite having a metal body.  It is also very fast to boil, but has no fancy features.  The only thing wrong with it so far is that the water level indicator does not start reading until you have at least 3 cups of water in it, and we fairly often want to boil smaller quantities, such as 1 cup to make up a white sauce packet.

I wouldn't bother with a quiet kettle. 
We've had a couple - current Russell Hobbs is the loudest we have ever had, which started its life in silence. It's the contrast that really makes the noise that much more unbearable. 

If a quiet kettle isn't descaled it will get noisy. A bit of white vinegar will fix it.

https://www.bbcgoodfood.com/howto/how-to-descale-a-kettle

fe31nz:

 

Consumer NZ has just today released their latest test of electric jugs and kettles.  Top of the list is the one we had just bought a couple of weeks before, the Russell Hobbs Montana RHK142.  It really is quiet, despite having a metal body.  It is also very fast to boil, but has no fancy features.  The only thing wrong with it so far is that the water level indicator does not start reading until you have at least 3 cups of water in it, and we fairly often want to boil smaller quantities, such as 1 cup to make up a white sauce packet.

 

They rank mine 3rd on the list and one of the quietist , A Smart Kettle, but it is actually really loud and think it has got louder. Notice that they rank some of the cheaper plastic kettles quite bad for noise when you would think plastic may not be as noisy 

lxsw20:

 

If a quiet kettle isn't descaled it will get noisy. A bit of white vinegar will fix it.

 

https://www.bbcgoodfood.com/howto/how-to-descale-a-kettle

 

Have done that and totally clean inside, but it doesn't affect the noise. 

Random thought...

Boiling water on induction is pretty much silent (maybe a bit of fan noise from the induction hob, depends what brand you use). And quite energy efficient.

Maybe get a decent portable 2kW induction hob (which can be used for all sorts of things apart from boiling water) and a decent stovetop kettle (rated for induction - radius of bottom should be large enough to decently cover the induction coils - don't get anything too small'n'tall).

Might take a little longer to get to boiling, but if it's quiet...

Just 2c.

Reflecting on this, the kettle noise also drives me crazy. Going to get a stovetop induction compatible kettle myself now :-)

When staying in a short stay apartment in Saigon we had a kettle which kept water at just under boiling temperature so made no noise.  Took a while to work out how it actually worked, you didn’t have to turn it on.  It was of Japanese design I believe and I could not comment on the efficiency of it but could be high if well insulated as you only re-heated the amount of water you used.

Further to induction stovetop as an alternative....

Had a dig around in the garage and found an old stovetop kettle we used to use on our gas hob years ago, which is induction compatible.

Breville 2.2kW jug - 1 Litre of tap water to boiling - 2m50s, Noisy as all crap. Hard to understand someone across the room without raising our voices. Google Assistant cannot interpret any commands.

Induction 2.2kW portable hob - 1 Litre of tap water to boiling at 100% power - 3m40s, half as noisy as kettle at a guess. Easy to talk across it at normal speaking volume and be understood. Google Assistant understands commands from meters away. 

Induction 2.2kW portable hob - 1 Litre of tap water to boiling at 50% power - 7m3s, a third or quarter as noisy as kettle at a guess. Really pretty quiet.

YMMV.....

I bought one of these https://www.dicksmith.co.nz/dn/buy/kogan-25l-2400w-hot-water-boiler-dispenser/ - does the trick just annoying its another kitchen appliance that needs to be filled up with water.

richms:

 

I bought one of these https://www.dicksmith.co.nz/dn/buy/kogan-25l-2400w-hot-water-boiler-dispenser/ - does the trick just annoying its another kitchen appliance that needs to be filled up with water.

 

It would be alright if you didn't need to fill it, but once you add the water level sensor, solenoid and Arduino, it starts getting a bit expensive.

SirHumphreyAppleby:

 

richms:

 

I bought one of these https://www.dicksmith.co.nz/dn/buy/kogan-25l-2400w-hot-water-boiler-dispenser/ - does the trick just annoying its another kitchen appliance that needs to be filled up with water.

 

 

It would be alright if you didn't need to fill it, but once you add the water level sensor, solenoid and Arduino, it starts getting a bit expensive.

 

I added a float valve to my coffee maker, but found that algae would grow in the tank without a periodic tipping out and wipe of it.

I just T'd off the filter that feeds the fridge - it had a thing that goes on the tap that drops the pressure to near nothing.

The shape of the water heating one means there is no flat surface to put the float valve on anyway.

There are under bench 'instant' water boilers common in office kitchenettes and high-end housing. Really nice and often also supply chilled water, but holy crap the pricing is horrendous. 

I probably could have gotten one from an office demolition and still regret not asking about taking it. 

We have a MultiTap Lia.  It has Filtered cold water (not chilled) and near boiling filtered water out the middle of the spout.  Once you have gone kettle-less  you wont go back.  Instant always, and quiet under bench.  Would recommend 100%