Siri AI in iOS 27 lets you pick a voice and then, in Apple’s words, “customize expressivity and pace until it clicks for you.” A deeper set of controls covering pitch, speed, tone and accent is limited to six iPhone models, according to the footnotes on Apple’s Apple Intelligence page: iPhone 18 Pro, iPhone 18 Pro Max, iPhone Duo, iPhone 17 Pro, iPhone 17 Pro Max and iPhone Air.
That split matters because every iPhone from the iPhone 15 Pro onward gets Siri AI itself. The voice-shaping controls sit on top of what Apple calls its advanced on-device model, and Apple lists the same hardware requirement for the improved on-device Dictation in iOS 27. The A20 Pro in this year’s phones is the newest chip on that list, and our A20 Pro chip explainer covers what its dual 16-core Neural Engine handles locally.
Key facts: Siri AI voice customization in iOS 27
| Item | Detail | Source |
|---|---|---|
| Basic controls | Choose a voice, then customize expressivity and pace | Apple’s iOS 27 page |
| Advanced controls | Pitch, speed, tone and accent | Apple’s Apple Intelligence page footnotes |
| iPhones with advanced controls | iPhone 18 Pro, 18 Pro Max, iPhone Duo, 17 Pro, 17 Pro Max, iPhone Air | Apple’s Apple Intelligence page |
| Other devices with advanced controls | iPad with M4 or later and 12GB or more unified memory, Mac with M3 or later and 12GB or more unified memory, Apple Vision Pro with M5 | Apple’s Apple Intelligence page |
| Shares the same requirement | Improved on-device Dictation | Apple’s Apple Intelligence page |
| Language at launch | English, with French, Japanese, Korean, Portuguese and Spanish in October | Apple’s press release |
| Status | Siri AI is beta in iOS 27, iPadOS 27, macOS 27, watchOS 27 and visionOS 27 | Apple’s Siri page |
| Release | iOS 27, Monday, September 14, 2026, free | Apple’s iOS 27 page |
What you can actually change about the voice
Apple describes two layers. The iOS 27 page keeps it simple: you pick a voice, then adjust expressivity and pace, which are the liveliness of the delivery and how quickly Siri speaks.
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The Apple Intelligence page goes further and names pitch, speed, tone and accent as the customizable characteristics, then footnotes them as requiring the advanced on-device model. Apple has not published the number of voices, their names, or the range each slider covers.
Voice is only part of the new assistant. Apple says Siri AI takes typed or spoken input, holds back-and-forth conversations, pulls personal context such as a photo from years ago or an email buried in your inbox, and takes actions in apps like Messages, Music and Reminders.
Which devices get the pitch, speed, tone and accent controls
| Device group | Siri AI | Pitch, speed, tone and accent |
|---|---|---|
| iPhone 18 Pro, 18 Pro Max, iPhone Duo | Yes | Yes |
| iPhone 17 Pro, 17 Pro Max, iPhone Air | Yes | Yes |
| iPhone 17, 17e, iPhone 16 family, 16e | Yes | Not listed by Apple |
| iPhone 15 Pro, 15 Pro Max | Yes | Not listed by Apple |
| iPhone 12 through iPhone 15 (non-Pro) | No Apple Intelligence | No |
| iPad with M4 or later, 12GB or more memory | Yes | Yes |
| Mac with M3 or later, 12GB or more memory | Yes | Yes |
| Apple Vision Pro with M5 | Yes | Yes |
The pattern is memory and chip generation rather than product tier: Apple’s own list stops at M4 for iPad and M3 for Mac, and in both cases adds a 12GB unified memory floor. Full specifications for this year’s phones are in our iPhone 18 Pro launch guide and iPhone Duo launch guide.
Where the settings live, and why the steps may shift
Apple has not published a support guide with steps for the iOS 27 Siri app or its voice controls. The step lists on Apple Support are still the current iOS 26 guides, so any Settings path you find today describes the shipping software, not the update.
For that reason we are not publishing a numbered walkthrough for a feature Apple has only described in marketing copy. Expect the controls to appear in Settings alongside Siri and Apple Intelligence once iOS 27 arrives on September 14, and expect the exact wording and order of the options to differ from the iOS 26 guides.
One extra note for anyone who moves between devices: Apple says the new Siri app uses iCloud to privately sync conversation history, so a chat started on Mac can continue on iPhone, iPad, Apple Watch or Apple Vision Pro. Apple has not said whether a voice choice syncs the same way.
What Apple has not said
- How many Siri AI voices there are, or what they are called.
- The range or units behind expressivity, pace, pitch, speed, tone and accent.
- Whether the accent options are tied to the English variant a device is set to.
- Whether voice settings sync across devices through iCloud the way conversation history does.
- Whether the advanced controls will reach older Apple Intelligence iPhones later.
- The size of the daily usage limits Apple applies to server-backed Siri AI requests, or the price of the expanded access it says will cost a fee in the future.
iOS 27 arrives as a free update on Monday, September 14, and Siri AI ships with it as a beta in English, with five more languages in October according to Apple’s press release. Apple’s pages also say Siri AI will not be available initially in the EU on iOS, iPadOS and watchOS, and Apple’s June release said the new Apple Intelligence features are on hold in China pending regulatory requirements. Our iOS 27 release day guide and full event recap track what changes on the day.
