We introduce a model of squeezing and noise reduction in the Ken effect tha
t accounts for noise in all quadratures of the driving field. Consequently
we show that Ken squeezing is much more sensitive to driving noise than squ
eezing produced by second harmonic generation (SHG). We experimentally demo
nstrate this sensitivity using a nonlinear system that tunes between strong
classical SHG and Ken behaviours. Whilst the system experiences strong squ
eezing in the SHG limit, it experiences no squeezing in the Ken limit, alth
ough it does experience strong classical noise reduction, or 'classical squ
eezing'.