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# Audio.Absorption

An object that holds a set of absorption data.

```
struct Absorption
```

## Overview

The Sabine absorption coefficient is a value between zero and one that describes the proportion of
incident sound energy a surface absorbs.

Create absorption data from an array of ten octave-band coefficients, a dictionary of
frequency–coefficient pairs, or a dictionary literal:

```swift
// From an array of ten octave-band coefficients:
let data = Audio.Absorption([0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10])

// From a dictionary of frequency–coefficient pairs:
let data = Audio.Absorption([500: 0.3, 1000: 0.4, 4000: 0.5])

// From a dictionary literal:
let data: Audio.Absorption = [500: 0.3, 1000: 0.4, 4000: 0.5]
```

## Topics

### Creating an absorption value

[`static func uniform(Float) -> Audio.Absorption`](/documentation/RealityKit/Audio/Absorption/uniform(_:))

Creates an absorption data set with the coefficient applied uniformly for every frequency.

### Scaling absorption

[`func scaled(by: (Float) -> Float) -> Audio.Absorption`](/documentation/RealityKit/Audio/Absorption/scaled(by:))

Scale the absorption data by a frequency-dependent scalar value between -1 and 1.

### Initializers

[`init(_:)`](/documentation/RealityKit/Audio/Absorption/init(_:))

Creates an absorption data set from a sequence of pairs of center frequency and Sabine absorption coefficient.

### Type Properties

[`static let `default`: Audio.Absorption`](/documentation/RealityKit/Audio/Absorption/default)

The default set of absorption data.

### Default Implementations

[ExpressibleByDictionaryLiteral Implementations](/documentation/RealityKit/Audio/Absorption/ExpressibleByDictionaryLiteral-Implementations)

## Relationships

### Conforms To

[`Sendable`](/documentation/Swift/Sendable)

[`Escapable`](/documentation/Swift/Escapable)

[`Hashable`](/documentation/Swift/Hashable)

[`Equatable`](/documentation/Swift/Equatable)

[`ExpressibleByDictionaryLiteral`](/documentation/Swift/ExpressibleByDictionaryLiteral)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Copyable`](/documentation/Swift/Copyable)

---

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