I would recommend listening to the potential generator you are thinking of buying before you buy. There can be a huge difference in decibel levels put out by different generators.
While it is not always the case it usually is. The inverter generator motors will not be running as fast as most conventional generators unless you are using the maximum power available. If you are only at half load it will be very unusual to find a conventional generator that will not be significantly louder than and inverter genset.
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