My Philips Hair Straightener is making a sizzling sound. Is this normal?

When the ION function is on, you will hear a sizzing sound coming from your straightener. The sizzling sound occurs, when your straightener releases millions of ions on both sides of the straightener to provide you with frizz-free smooth and shiny hair.

Note: The Philips 8000 Series may release a loud sizzling sound, this is normal and nothing to worry about.