My compact Panasonic, the brand that invented Inverter tech that reduces the size of the transformer and allows true gradient level of power vs cycling the magnetron on and off constantly, only beeps five times at the end of cooking time.
I've always thought the beeps at the end of the cooking cycle are just to let you know what you have in there is done cooking, much like an egg timer goes off after the time runs down. If it adds a 10 sec countdown, it could be just to let the food cool down a bit. My Panny actually has a fan that kicks on at the end of cooking time if the cooking cycle is a hot one, which it can detect via heat sensors. The fans expel the heat quickly, and also odors I find.
Anyone that uses a microwave a lot but hasn't ever had one with inverter technology really ought to look into it. I would say in laymen's terms it's a bit like analog vs digital, meaning a microwave without it is either on full power, or off, cycling back and forth between the two. This means the molecules in the food cycle between being super excited, or relaxing. Food does not like to be cooked this way, it is not a natural, even way of cooking. It makes them go back and forth between being super hot, and cooling down.
Another thing I like about the design of my Panny is it has actual metal buttons and a metal dial that pops out when you tap it, and back in flush when you push it again. I detest the sense touch panels many microwaves have, and they are often one of the first things that fails on ones that have them. The dial on mine is what sets time or levels of defrost, etc. I rarely use my microwave full power, and when I do, it's for things like quickly heating a mug half full of hot tap water and Alpine Cider mix, which I zap for a minute full power, then fill the mug full with more hot tap water. I usually set the Power level to 6, which is roughly 600 watt as this unit is 950 watts at full power. This power is perfect for warming 3 cold slices of pizza (2 min), or warming a bowl of soup (2.5 min).
This microwave is also excellent at defrosting with it's Turbo Defrost feature. I use it every morning at level one to thaw my frozen Blueberries, which I buy fresh in 18 oz size. I select level 1 with the dial after tapping the Turbo Defrost button. Level one lets it go 36 sec. I then after scooping out 3 oz of Greek Yogurt, go through the same process with the microwave, but this time open the door when the 36 sec counts down to 27.
Turbo Defrost is also great for thawing my 1 Lb packs of Land o Frost sliced turkey I use for my sandwich at lunch if I forget to put a pack in the fridge when I run out of it the day before. I just set it to Turbo Defrost level 2 (1 min 10 sec), and run it a few times that way, turning it over and flipping it end to end each time. The only slight neg of this microwave is it did not come with a thorough manual on how to use it, so much of getting to know what works well is via trial and error.