Smile is an audio de-harshing plugin designed to enhance sound clarity by adapting frequency response to the way humans perceive hearing. It utilizes principles based on the Fletcher-Munson curves, which describe how our ears detect different frequencies at varying volume levels. This approach allows Smile to effectively reduce harshness in audio signals while maintaining natural tonal balance.

Equipped with a transient recovery engine, Smile enables users to apply strong processing without causing the sound to become dull or lifeless. Additionally, the plugin includes filters that manage extreme frequencies at both the low and high ends, aligning with the Fletcher-Munson curve to ensure a smooth and pleasant listening experience. This makes Smile ideal for refining audio tracks that need subtle yet impactful tonal adjustments.

Recent updates have introduced a Delta-function feature, offering improved transient preview capabilities, especially on high-resolution displays. The transient detection mechanism is now stereo, accompanied by a linking control that allows users to adjust between independent and fully linked stereo processing. Notably, Smile version 3.5 is now available for free, making this highly effective de-harsher accessible to a wide range of users.