If resistance rises, current flow decreases. If the voltage is increased proportional to the rise of resistance, the current will remain the same.
hiss - a fricative sound (especially as an expression of disapproval); the performers could not be heard over the hissing of the audience fizzle, hissing, hushing, sibilation noise - sound of any kind (especially unintelligible or dissonant sound); he enjoyed the street noises; they heard indistinct noises of people talking; during the firework display that ended the gala the noise reached 98 decibels
A hissing or, popping sound when the water heater is reheating is one of the more common sounds a water heater makes. When water is heated the water molecules expand taking up more room leaving less room for other things in the solution.