---
title: virtualFormat
framework: Core Audio
role: symbol
role_heading: Instance Property
platforms: [macOS 15.0+]
path: coreaudio/audiohardwarestream/virtualformat
---

# virtualFormat

An AudioStreamBasicDescription that describes the current data format for the stream. The virtual format refers to the data format in which all IOProcs for the owning device will perform IO transactions.

## Declaration

```swift
var virtualFormat: AudioStreamBasicDescription { get throws }
```