---
title: kSpeechPitchBaseProperty
framework: applicationservices
role: symbol
role_heading: Global Variable
path: applicationservices/kspeechpitchbaseproperty
---

# kSpeechPitchBaseProperty

Get or set the speech channel’s baseline speech pitch.

## Declaration

```swift
let kSpeechPitchBaseProperty: CFString
```

## Discussion

Discussion The value associated with this property is a CFNumber object that specifies the speech channel’s baseline speech pitch.  Typical voice frequencies range from around 90 hertz for a low-pitched male voice to perhaps 300 hertz for a high-pitched child’s voice. These frequencies correspond to approximate pitch values in the ranges of 30.000 to 40.000 and 55.000 to 65.000, respectively. This property works with the CopySpeechProperty(_:_:_:) and SetSpeechProperty(_:_:_:) functions. note: The change in speech pitch may not be noticeable until the next sentence or paragraph is spoken.