---
title: volume
framework: appkit
role: symbol
role_heading: Instance Property
path: appkit/nsspeechsynthesizer/volume
---

# volume

The synthesizer’s speaking volume.

## Declaration

```swift
var volume: Float { get set }
```

## Discussion

Discussion Volumes are expressed in floating-point units ranging from 0.0 through 1.0. A value of 0.0 corresponds to silence, and a value of 1.0 corresponds to the maximum possible volume. Volume units lie on a scale that is linear with amplitude or voltage. A doubling of perceived loudness corresponds to a doubling of the volume. Setting a value outside this range is undefined.

## See Also

### Configuring Speech Synthesizers

- [usesFeedbackWindow](appkit/nsspeechsynthesizer/usesfeedbackwindow.md)
- [voice()](appkit/nsspeechsynthesizer/voice().md)
- [setVoice(_:)](appkit/nsspeechsynthesizer/setvoice(_:).md)
- [rate](appkit/nsspeechsynthesizer/rate.md)