SpeechAnalyzer Speech-to-Text

Implement speech-to-text with Apple's new SpeechAnalyzer API (iOS 26+). Powers Notes, Voice Memos, Journal, and Call Summarization.

Overview

SpeechAnalyzer is Apple's next-generation speech-to-text API:

• On-device processing - Private, no server required
• Long-form audio - Optimized for meetings, lectures, conversations
• Distant audio - Works well with speakers across the room
• Volatile results - Real-time approximate results while processing
• Timing metadata - Sync text with audio playback
• Model management - System handles model downloads and updates

When to Use This Skill

Use when you need to:

• ☑ Transcribe live audio (microphone)
• ☑ Transcribe audio files
• ☑ Build Notes-like or Voice Memos-like features
• ☑ Show real-time transcription feedback
• ☑ Sync transcription with audio playback
• ☑ Choose between SpeechAnalyzer and SFSpeechRecognizer

Example Prompts

• "How do I add speech-to-text to my iOS app?"
• "What's the difference between SpeechAnalyzer and SFSpeechRecognizer?"
• "How do I show real-time transcription while recording?"
• "How do I handle volatile vs finalized transcription results?"
• "How do I sync transcript text with audio playback?"

Key Decision Trees

SpeechAnalyzer vs SFSpeechRecognizer

Need speech-to-text?
├─ iOS 26+ only?
│   └─ Yes → SpeechAnalyzer (preferred)
├─ Need iOS 10-25 support?
│   └─ Yes → SFSpeechRecognizer (or DictationTranscriber)
├─ Long-form audio (meetings, lectures)?
│   └─ Yes → SpeechAnalyzer
└─ Distant audio (across room)?
    └─ Yes → SpeechAnalyzer

Common Use Cases

File Transcription (Simplest)

import Speech

func transcribe(file: URL, locale: Locale) async throws -> AttributedString {
    let transcriber = SpeechTranscriber(
        locale: locale,
        preset: .offlineTranscription
    )

    async let result = try transcriber.results
        .reduce(AttributedString()) { $0 + $1.text }

    let analyzer = SpeechAnalyzer(modules: [transcriber])

    if let lastSample = try await analyzer.analyzeSequence(from: file) {
        try await analyzer.finalizeAndFinish(through: lastSample)
    } else {
        await analyzer.cancelAndFinishNow()
    }

    return try await result
}

Live Transcription Setup

// 1. Configure transcriber with volatile results
let transcriber = SpeechTranscriber(
    locale: Locale.current,
    reportingOptions: [.volatileResults],
    attributeOptions: [.audioTimeRange]
)

// 2. Create analyzer
let analyzer = SpeechAnalyzer(modules: [transcriber])

// 3. Get required audio format
let format = await SpeechAnalyzer.bestAvailableAudioFormat(
    compatibleWith: [transcriber]
)

// 4. Ensure model is available
if let downloader = try await AssetInventory.assetInstallationRequest(
    supporting: [transcriber]
) {
    try await downloader.downloadAndInstall()
}

// 5. Start analyzer
let (stream, builder) = AsyncStream<AnalyzerInput>.makeStream()
try await analyzer.start(inputSequence: stream)

Handle Results

for try await result in transcriber.results {
    if result.isFinal {
        // Finalized - won't change
        finalTranscript += result.text
        volatileTranscript = AttributedString()
    } else {
        // Volatile - will be replaced
        volatileTranscript = result.text
    }
}

Common Pitfalls

• ❌ Forgetting to call finalizeAndFinishThroughEndOfInput() (loses volatile results)
• ❌ Not converting audio to bestAvailableAudioFormat
• ❌ Skipping model availability check before use
• ❌ Not clearing volatile results when finalized arrives

Platform Support

Feature	Availability
SpeechTranscriber	iOS 26+, macOS Tahoe+
DictationTranscriber	iOS 26+, macOS Tahoe+, watchOS 26+
SFSpeechRecognizer	iOS 10+ (legacy)

Related

• CoreML — deploy custom speech/audio ML models when SpeechAnalyzer doesn't meet your needs
• Foundation Models — generate summaries or titles from transcribed text using Apple Intelligence

WWDC Sessions

• WWDC25-277: Bring advanced speech-to-text with SpeechAnalyzer

Apple Documentation

• Speech Framework