noisy kettles

[Dizmal]

Why are electric kettles with a central base connection so noisy when boiling compared to those with the connection at the back?

[dipee65]

Could be because the base, which is probably hollow, is acting like a sound board and ammplifying the sound.

[Dizmal]

But that would also affect kettles with the rear connection, yet those kettles bubble away fairly quietly. The centre connection kettles all seem to roar like a jet engine and necessitate me turning up the volume on the radio!