# Hanning

> Hanning (Hann) window for FFT spectrum analysis.

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine](/engine/6000.5/script-reference/unityengine.md)
* **Assembly:** UnityEngine.AudioModule

```csharp
Hanning = 3
```

### Remarks

Window function: `W[n] = 0.5 * (1.0 - cos(2π * n/N))`, where `n` is the sample index and `N` is the window length. This is also known as the Hann window.

Pass this value to the `window` parameter of [AudioListener.GetSpectrumData](/engine/6000.5/script-reference/unityengine/audiolistener/getspectrumdata.md) or [AudioSource.GetSpectrumData](/engine/6000.5/script-reference/unityengine/audiosource/getspectrumdata.md). The window is applied before the FFT to reduce spectral leakage between frequency bins.

The Hanning window is a common general-purpose raised-cosine window, similar to [FFTWindow.Hamming](/engine/6000.5/script-reference/unityengine/fftwindow/hamming.md). Use Hanning when you want smooth tapering at the block edges; compare with Hamming if you need slightly different sidelobe behavior. For stronger leakage control, use [FFTWindow.Blackman](/engine/6000.5/script-reference/unityengine/fftwindow/blackman.md) or [FFTWindow.BlackmanHarris](/engine/6000.5/script-reference/unityengine/fftwindow/blackmanharris.md).

Additional Resources: [FFTWindow](/engine/6000.5/script-reference/unityengine/fftwindow.md), [FFTWindow.Hamming](/engine/6000.5/script-reference/unityengine/fftwindow/hamming.md).