Fix silent live preview on stereo and multi-input audio interfaces

AVAudioConverter keeps only channel 1 when downmixing stereo and outputs
pure silence for layout-less multi-channel inputs (e.g. a 4-input USB
interface such as the UA Volt 476P), so the dictation model heard nothing
and the HUD never showed text. Pick the channel that carries the voice
(loudest on smoothed energy, switching only on a clear 6 dB margin) and
convert it as mono. Also reserve the dictation locale, which the Speech
framework warns will become required, and log the mic format.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -12,6 +12,10 @@ A simple menu bar app for voice dictation using OpenAI Whisper (local, offline).
 
 ## macOS
 
+### What's new in 1.4.0
+
+- 💬 **Live preview while recording** — the recording overlay shows what you're saying as you speak, using macOS's on-device dictation model (works in Hungarian too). It's a preview: the pasted text still comes from Whisper, so it can differ slightly. Toggle it in Settings.
+
 ### What's new in 1.3.1
 
 - 🪶 **Quantized models** — *Large v3 Turbo q5_0* keeps the transcription server at ~0.7 GB RAM instead of ~1.75 GB, at the same speed (also Small q5_1, Medium q5_0, Turbo q8_0 and Large v3 q5_0)
@@ -29,6 +33,7 @@ A simple menu bar app for voice dictation using OpenAI Whisper (local, offline).
 - 🎤 Global hotkey (⌃⌥D) to start/stop recording
 - ⚡ Fast transcription via a warm whisper-server (model stays loaded — no per-dictation reload), with automatic fallback to `whisper-cli`
 - 📊 Live mic-level meter while recording, with a "no audio input" warning
+- 💬 Live transcript preview in the recording overlay (on-device Apple dictation model; Whisper still produces the pasted text)
 - 📖 Custom dictionary (heard → replacement) that also biases recognition
 - 🔒 Fully offline - uses local Whisper model
 - ⌨️ Automatic paste into any focused app
@@ -42,7 +47,7 @@ A simple menu bar app for voice dictation using OpenAI Whisper (local, offline).
 
 ### Requirements
 
-- macOS 13.0+
+- macOS 26 (Tahoe) or later
 - Apple Silicon (M1/M2/M3) or Intel Mac
 
 ### Quick Install (Download)
@@ -93,6 +98,7 @@ Click the menu bar icon → Settings to configure:
 - **Model**: Select from installed models or download new ones (✓ marks models already downloaded)
 - **Dictionary**: Add *Heard → Replacement* pairs to fix names/jargon (use `\n` for a newline); the replacement terms also improve recognition
 - **Sound feedback**: Toggle audio feedback on/off
+- **Live preview while recording**: Show a rough live transcript in the recording overlay (on by default)
 - **Launch at login**: Start automatically when you log in
 
 ### Whisper Models
@@ -145,6 +151,7 @@ Grant these in System Settings → Privacy & Security:
 ## Security
 
 - All processing is done locally - no data leaves your device
+- The live preview uses macOS's on-device dictation model (SpeechAnalyzer); it needs no extra permission beyond the microphone
 - The bundled `whisper-server` is bound to `127.0.0.1` (loopback only) and is never exposed on the network
 - Audio files are stored in private temp directory and deleted after transcription
 - Clipboard is cleared after paste (transcript doesn't remain accessible)

macos/Makefile

@@ -2,7 +2,7 @@
 
 APP_NAME = WhisperDictate
 APP_BUNDLE = $(APP_NAME).app
-VERSION = 1.3.1
+VERSION = 1.4.0
 
 # Directories
 SRC_DIR = src
@@ -11,7 +11,7 @@ BUNDLE_DIR = $(APP_BUNDLE)/Contents
 
 # Compiler settings
 SWIFT = swiftc
-SWIFT_FLAGS = -O -framework Cocoa -framework AVFoundation -framework Carbon -framework CoreGraphics -framework ServiceManagement
+SWIFT_FLAGS = -O -framework Cocoa -framework AVFoundation -framework Speech -framework Carbon -framework CoreGraphics -framework ServiceManagement
 
 .PHONY: all clean build bundle install run dmg
 

macos/WhisperDictate.app/Contents/Info.plist

@@ -19,9 +19,9 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.3.1</string>
+	<string>1.4.0</string>
 	<key>CFBundleVersion</key>
-	<string>4</string>
+	<string>5</string>
 	<key>LSMinimumSystemVersion</key>
 	<string>13.0</string>
 	<key>LSUIElement</key>

macos/src/main.swift

@@ -1,5 +1,6 @@
 import Cocoa
-import AVFoundation
+@preconcurrency import AVFoundation
+@preconcurrency import Speech
 import Carbon.HIToolbox
 import ServiceManagement
 import ApplicationServices
@@ -11,6 +12,7 @@ struct Defaults {
     static let modelPath = "whisperModelPath"
     static let playSounds = "playSounds"
     static let replacements = "customReplacements"
+    static let livePreview = "livePreview"
 }
 
 // MARK: - Whisper Models
@@ -411,6 +413,208 @@ final class WhisperServer {
 // A small floating, non-interactive panel shown while recording. Doubles as a
 // diagnostic: if the input stays silent it flags "no input" — exactly the
 // failure that silently produced empty recordings + whisper hallucinations.
+// MARK: - Live Preview (on-device Apple dictation model)
+// Streams a rough live transcript into the recording HUD using the system's
+// on-device dictation model (SpeechAnalyzer + DictationTranscriber, macOS 26).
+// It is only a preview: the pasted text still comes from Whisper. It captures
+// the microphone with its own AVAudioEngine so the AVAudioRecorder path used
+// for Whisper stays untouched; if anything here fails there is simply no preview.
+final class LivePreview {
+    // Called on the main thread with the transcript so far
+    var onText: ((String) -> Void)?
+
+    private var session = 0
+    private var engine: AVAudioEngine?
+    private var analyzer: SpeechAnalyzer?
+    private var input: AsyncStream<AnalyzerInput>.Continuation?
+    private var resultsTask: Task<Void, Never>?
+
+    // App language code -> supported dictation locale ("hu" -> hu-HU); nil if unsupported
+    static func locale(for languageCode: String) async -> Locale? {
+        let requested = languageCode == SupportedLanguages.autoDetect ? Locale.current : Locale(identifier: languageCode)
+        return await DictationTranscriber.supportedLocale(equivalentTo: requested)
+    }
+
+    private static func makeTranscriber(locale: Locale) -> DictationTranscriber {
+        DictationTranscriber(locale: locale, contentHints: [], transcriptionOptions: [.punctuation],
+                             reportingOptions: [.volatileResults, .frequentFinalization], attributeOptions: [])
+    }
+
+    // Download the on-device model for this language in the background if it's missing
+    static func installModelIfNeeded(languageCode: String) {
+        Task {
+            guard let locale = await locale(for: languageCode) else { return }
+            do {
+                if let request = try await AssetInventory.assetInstallationRequest(supporting: [makeTranscriber(locale: locale)]) {
+                    NSLog("Live preview: installing dictation model for \(locale.identifier)")
+                    try await request.downloadAndInstall()
+                    NSLog("Live preview: dictation model installed for \(locale.identifier)")
+                }
+            } catch {
+                NSLog("Live preview: model install failed: \(error)")
+            }
+        }
+    }
+
+    func start(languageCode: String, contextualStrings: [String]) {
+        stop()
+        let current = session
+        Task { @MainActor in
+            do {
+                guard let locale = await LivePreview.locale(for: languageCode) else {
+                    NSLog("Live preview: no on-device dictation model for '\(languageCode)'")
+                    return
+                }
+                let transcriber = LivePreview.makeTranscriber(locale: locale)
+                // Even when the model is already on disk the app may first have to register it;
+                // that takes a fraction of a second. A real download just means no preview this time.
+                _ = try? await AssetInventory.reserve(locale: locale)
+                if await AssetInventory.status(forModules: [transcriber]) != .installed,
+                   let request = try await AssetInventory.assetInstallationRequest(supporting: [transcriber]) {
+                    NSLog("Live preview: preparing dictation model for \(locale.identifier)")
+                    try await request.downloadAndInstall()
+                }
+                guard current == self.session,
+                      let analyzerFormat = await SpeechAnalyzer.bestAvailableAudioFormat(compatibleWith: [transcriber]) else { return }
+
+                // Start the microphone first; the stream buffers audio until the analyzer is running,
+                // so the first words aren't lost while the model spins up.
+                let (stream, continuation) = AsyncStream<AnalyzerInput>.makeStream()
+                let engine = AVAudioEngine()
+                let micFormat = engine.inputNode.outputFormat(forBus: 0)
+                guard micFormat.sampleRate > 0, current == self.session,
+                      let monoFormat = AVAudioFormat(standardFormatWithSampleRate: micFormat.sampleRate, channels: 1),
+                      let converter = AVAudioConverter(from: monoFormat, to: analyzerFormat) else { return }
+                NSLog("Live preview: mic %d ch @ %.0f Hz -> %@", micFormat.channelCount, micFormat.sampleRate, analyzerFormat.description)
+                engine.inputNode.installTap(onBus: 0, bufferSize: 4096, format: micFormat,
+                                            block: LivePreview.tapBlock(converter: converter, format: analyzerFormat, continuation: continuation))
+                try engine.start()
+                self.engine = engine
+                self.input = continuation
+
+                let analyzer = SpeechAnalyzer(modules: [transcriber])
+                self.analyzer = analyzer
+                if !contextualStrings.isEmpty {
+                    let context = AnalysisContext()
+                    context.contextualStrings[.general] = contextualStrings
+                    try await analyzer.setContext(context)
+                }
+                self.resultsTask = Task { @MainActor [weak self] in
+                    // Finalized segments accumulate; the volatile tail is replaced on every update
+                    var finalized = ""
+                    do {
+                        for try await result in transcriber.results {
+                            let text = String(result.text.characters)
+                            let shown = LivePreview.join(finalized, text)
+                            if result.isFinal { finalized = shown }
+                            guard let self = self, current == self.session else { return }
+                            self.onText?(shown)
+                        }
+                    } catch {
+                        NSLog("Live preview: results ended: \(error)")
+                    }
+                }
+                guard current == self.session else { return }  // stop() already tore everything down
+                try await analyzer.start(inputSequence: stream)
+            } catch {
+                NSLog("Live preview failed: \(error)")
+                if current == self.session { self.stop() }
+            }
+        }
+    }
+
+    func stop() {
+        session += 1
+        if let engine = engine {
+            engine.inputNode.removeTap(onBus: 0)
+            engine.stop()
+        }
+        engine = nil
+        input?.finish()
+        input = nil
+        resultsTask?.cancel()
+        resultsTask = nil
+        if let analyzer = analyzer {
+            Task { await analyzer.cancelAndFinishNow() }
+        }
+        analyzer = nil
+    }
+
+    // Segments don't always carry a separating space
+    static func join(_ head: String, _ tail: String) -> String {
+        guard let last = head.last, let first = tail.first, !last.isWhitespace, !first.isWhitespace else { return head + tail }
+        return head + " " + tail
+    }
+
+    // Runs on the audio thread: take the voice channel as mono, convert it to the
+    // analyzer's format. Built in a static context so it carries no actor assumptions.
+    private static func tapBlock(converter: AVAudioConverter, format: AVAudioFormat,
+                                 continuation: AsyncStream<AnalyzerInput>.Continuation) -> AVAudioNodeTapBlock {
+        let downmixer = VoiceChannelPicker()
+        return { micBuffer, _ in
+            guard let buffer = downmixer.mono(from: micBuffer) else { return }
+            let ratio = format.sampleRate / buffer.format.sampleRate
+            let capacity = AVAudioFrameCount(Double(buffer.frameLength) * ratio) + 64
+            guard let out = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: capacity) else { return }
+            var consumed = false
+            var error: NSError?
+            converter.convert(to: out, error: &error) { _, status in
+                if consumed {
+                    status.pointee = .noDataNow
+                    return nil
+                }
+                consumed = true
+                status.pointee = .haveData
+                return buffer
+            }
+            if error == nil, out.frameLength > 0 {
+                continuation.yield(AnalyzerInput(buffer: out))
+            }
+        }
+    }
+}
+
+// Picks the input channel that carries the voice and returns it as a mono buffer.
+// AVAudioConverter keeps only channel 1 when downmixing stereo, and outputs pure
+// silence for layout-less multi-channel inputs (e.g. a 4-input USB interface),
+// so the live preview model would hear nothing. The loudest channel is chosen on
+// smoothed energy, and only replaced by one that is clearly (6 dB) louder.
+final class VoiceChannelPicker {
+    private var energy: [Float] = []
+    private var active = 0
+    private var monoFormat: AVAudioFormat?
+
+    func mono(from buffer: AVAudioPCMBuffer) -> AVAudioPCMBuffer? {
+        let channels = Int(buffer.format.channelCount)
+        let frames = Int(buffer.frameLength)
+        guard frames > 0, let data = buffer.floatChannelData else { return nil }
+        if channels == 1 { return buffer }
+
+        if energy.count != channels {
+            energy = Array(repeating: 0, count: channels)
+            active = 0
+        }
+        for c in 0..<channels {
+            var sum: Float = 0
+            for i in 0..<frames { sum += data[c][i] * data[c][i] }
+            energy[c] = energy[c] * 0.9 + sum / Float(frames) * 0.1
+        }
+        if let loudest = energy.indices.max(by: { energy[$0] < energy[$1] }), energy[loudest] > energy[active] * 4 {
+            active = loudest
+        }
+
+        if monoFormat?.sampleRate != buffer.format.sampleRate {
+            monoFormat = AVAudioFormat(standardFormatWithSampleRate: buffer.format.sampleRate, channels: 1)
+        }
+        guard let format = monoFormat,
+              let out = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: AVAudioFrameCount(frames)),
+              let dest = out.floatChannelData else { return nil }
+        dest[0].update(from: data[active], count: frames)
+        out.frameLength = AVAudioFrameCount(frames)
+        return out
+    }
+}
+
 final class MeterView: NSView {
     enum Mode { case recording, transcribing }
     enum Notice { case loadingModel, modelLoaded }
@@ -419,15 +623,55 @@ final class MeterView: NSView {
     private var silent = false
     var mode = Mode.recording { didSet { needsDisplay = true } }
     var notice: Notice? { didSet { needsDisplay = true } }
+    var previewText: String? { didSet { if previewText != oldValue { cachedPreview = nil; needsDisplay = true } } }
+    var hasPreview: Bool { previewBlock() != nil }
 
-    // Height for the current mode + notice
+    private static let maxPreviewLines = 3
+    private static let previewFont = NSFont.systemFont(ofSize: 13)
+    private var cachedPreview: (width: CGFloat, text: NSAttributedString, height: CGFloat)?
+
+    private var noticeHeight: CGFloat {
+        switch notice {
+        case .loadingModel?: return 35
+        case .modelLoaded?: return 19
+        case nil: return 0
+        }
+    }
+
+    // Height for the current mode, notice and live preview text
     var preferredHeight: CGFloat {
         let base: CGFloat = mode == .recording ? 72 : 44
-        switch notice {
-        case .loadingModel?: return base + 34
-        case .modelLoaded?: return base + 20
-        case nil: return base
+        let preview = previewBlock().map { 6 + $0.height } ?? 0
+        return base + noticeHeight + preview
+    }
+
+    // The tail of the live transcript that fits in a few lines; older words scroll off the top
+    private func previewBlock() -> (text: NSAttributedString, height: CGFloat)? {
+        guard let raw = previewText, !raw.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else { return nil }
+        let width = bounds.width - 32
+        if let cached = cachedPreview, cached.width == width { return (cached.text, cached.height) }
+
+        let attrs: [NSAttributedString.Key: Any] = [
+            .font: MeterView.previewFont,
+            .foregroundColor: NSColor(calibratedWhite: 1, alpha: 0.92)
+        ]
+        func measure(_ string: NSAttributedString) -> CGFloat {
+            ceil(string.boundingRect(with: NSSize(width: width, height: 10_000), options: [.usesLineFragmentOrigin, .usesFontLeading]).height)
         }
+        let lineHeight = measure(NSAttributedString(string: "Ag", attributes: attrs))
+        let maxHeight = lineHeight * CGFloat(MeterView.maxPreviewLines) + 1
+
+        let words = raw.split(whereSeparator: { $0.isWhitespace })
+        var dropped = 0
+        var text = NSAttributedString(string: words.joined(separator: " "), attributes: attrs)
+        var height = measure(text)
+        while height > maxHeight && dropped < words.count - 1 {
+            dropped += 1
+            text = NSAttributedString(string: "…" + words[dropped...].joined(separator: " "), attributes: attrs)
+            height = measure(text)
+        }
+        cachedPreview = (width, text, height)
+        return (text, height)
     }
 
     func set(level: CGFloat, silent: Bool) {
@@ -435,7 +679,7 @@ final class MeterView: NSView {
         self.silent = silent
         needsDisplay = true
     }
-    func reset() { level = 0; silent = false; mode = .recording; notice = nil; needsDisplay = true }
+    func reset() { level = 0; silent = false; mode = .recording; notice = nil; previewText = nil; needsDisplay = true }
 
     override func draw(_ dirtyRect: NSRect) {
         let bg = NSBezierPath(roundedRect: bounds, xRadius: 12, yRadius: 12)
@@ -472,6 +716,12 @@ final class MeterView: NSView {
             break
         }
 
+        if let preview = previewBlock() {
+            let top = textY - 6
+            preview.text.draw(with: NSRect(x: 16, y: top - preview.height, width: bounds.width - 32, height: preview.height),
+                              options: [.usesLineFragmentOrigin, .usesFontLeading])
+        }
+
         guard mode == .recording else { return }
 
         let segs = 20
@@ -496,7 +746,7 @@ final class MeterView: NSView {
 
 final class RecordingHUD {
     private var window: NSWindow?
-    private let meter = MeterView(frame: NSRect(x: 0, y: 0, width: 320, height: 72))
+    private let meter = MeterView(frame: NSRect(x: 0, y: 0, width: 420, height: 72))
 
     func show() {
         meter.reset()
@@ -512,6 +762,13 @@ final class RecordingHUD {
         layout()
     }
 
+    func setPreview(_ text: String?) {
+        meter.previewText = text
+        layout()
+    }
+
+    var hasPreview: Bool { meter.hasPreview }
+
     // Stay up after recording while a slow (model-loading) transcription runs
     func showTranscribing(notice: MeterView.Notice?) {
         makeWindowIfNeeded()
@@ -533,7 +790,7 @@ final class RecordingHUD {
 
     private func makeWindowIfNeeded() {
         if window == nil {
-            let w = NSPanel(contentRect: NSRect(x: 0, y: 0, width: 320, height: 72),
+            let w = NSPanel(contentRect: NSRect(x: 0, y: 0, width: 420, height: 72),
                             styleMask: [.borderless, .nonactivatingPanel],
                             backing: .buffered, defer: false)
             w.isOpaque = false
@@ -786,6 +1043,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
     var settingsWindowController: NSWindowController?
     var whisperServer: WhisperServer?
     let recordingHUD = RecordingHUD()
+    let livePreview = LivePreview()
     var meterTimer: Timer?
     var silenceStart: Date?
     weak var dictTable: NSTableView?
@@ -814,6 +1072,11 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
         set { UserDefaults.standard.set(newValue, forKey: Defaults.playSounds) }
     }
 
+    var livePreviewEnabled: Bool {
+        get { UserDefaults.standard.object(forKey: Defaults.livePreview) as? Bool ?? true }
+        set { UserDefaults.standard.set(newValue, forKey: Defaults.livePreview) }
+    }
+
     // Custom dictionary: ordered list of ["from": recognised, "to": replacement].
     var replacements: [[String: String]] {
         get { (UserDefaults.standard.array(forKey: Defaults.replacements) as? [[String: String]]) ?? [] }
@@ -823,11 +1086,16 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
     // Whisper initial prompt built from the desired ("to") terms, to bias
     // recognition toward the user's names/jargon. Returns nil if empty.
     func customPrompt() -> String? {
-        let terms = replacements.compactMap { $0["to"] }
+        let terms = dictionaryTerms()
+        return terms.isEmpty ? nil : terms.joined(separator: ", ")
+    }
+
+    // The desired ("to") dictionary terms, also given to the live preview model
+    func dictionaryTerms() -> [String] {
+        replacements.compactMap { $0["to"] }
             .map { $0.replacingOccurrences(of: "\\n", with: " ") }
             .map { $0.trimmingCharacters(in: .whitespaces) }
             .filter { !$0.isEmpty }
-        return terms.isEmpty ? nil : terms.joined(separator: ", ")
     }
 
     // Apply the dictionary find/replace pairs to a transcript. "\n" in a
@@ -858,6 +1126,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
         }
 
         checkAccessibilityPermission()
+        if livePreviewEnabled { LivePreview.installModelIfNeeded(languageCode: language) }
 
         NSLog("WhisperDictate started. Press ⌃⌥D to toggle recording.")
     }
@@ -1091,7 +1360,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
 
     func createSettingsWindow() -> NSWindow {
         let window = NSWindow(
-            contentRect: NSRect(x: 0, y: 0, width: 450, height: 540),
+            contentRect: NSRect(x: 0, y: 0, width: 450, height: 580),
             styleMask: [.titled, .closable],
             backing: .buffered,
             defer: false
@@ -1102,7 +1371,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
 
         let contentView = NSView(frame: window.contentView!.bounds)
 
-        var y: CGFloat = 498
+        var y: CGFloat = 538
         let labelWidth: CGFloat = 120
         let controlX: CGFloat = 140
         let controlWidth: CGFloat = 280
@@ -1180,6 +1449,15 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
         loginCheck.state = isLaunchAtLoginEnabled() ? .on : .off
         contentView.addSubview(loginCheck)
 
+        y -= 40
+
+        // Live preview
+        let previewCheck = NSButton(checkboxWithTitle: "Live preview while recording", target: self, action: #selector(livePreviewChanged(_:)))
+        previewCheck.frame = NSRect(x: controlX, y: y, width: controlWidth, height: 24)
+        previewCheck.state = livePreviewEnabled ? .on : .off
+        previewCheck.toolTip = "Shows a rough live transcript in the recording overlay using macOS's on-device dictation model. The pasted text still comes from Whisper."
+        contentView.addSubview(previewCheck)
+
         // Custom dictionary (recognised -> replacement)
         let dictLabel = NSTextField(labelWithString: "Dictionary (heard → replacement):")
         dictLabel.frame = NSRect(x: 20, y: 304, width: 300, height: 20)
@@ -1247,6 +1525,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
     @objc func languageChanged(_ sender: NSPopUpButton) {
         if let code = sender.selectedItem?.representedObject as? String {
             language = code
+            if livePreviewEnabled { LivePreview.installModelIfNeeded(languageCode: code) }
             NSLog("Language changed to: \(language)")
         }
     }
@@ -1330,6 +1609,11 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
         }
     }
 
+    @objc func livePreviewChanged(_ sender: NSButton) {
+        livePreviewEnabled = sender.state == .on
+        if livePreviewEnabled { LivePreview.installModelIfNeeded(languageCode: language) }
+    }
+
     @objc func playSoundsChanged(_ sender: NSButton) {
         playSounds = sender.state == .on
     }
@@ -1562,6 +1846,7 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
             NSLog("Recording started")
             startMeter()
             prepareModelForDictation()
+            startLivePreview()
         } catch {
             NSLog("Recording failed: \(error)")
             if playSounds { NSSound(named: "Basso")?.play() }
@@ -1603,6 +1888,16 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
         checkModelLoaded()
     }
 
+    // MARK: - Live preview
+    func startLivePreview() {
+        guard livePreviewEnabled else { return }
+        livePreview.onText = { [weak self] text in
+            guard let self = self, self.isRecording else { return }
+            self.recordingHUD.setPreview(self.applyReplacements(text))
+        }
+        livePreview.start(languageCode: language, contextualStrings: dictionaryTerms())
+    }
+
     // MARK: - Model warm-up
     // Start getting the model into memory as soon as recording starts, so loading
     // overlaps with the user talking instead of following it. Only if that turns
@@ -1659,10 +1954,13 @@ class AppDelegate: NSObject, NSApplicationDelegate, URLSessionDownloadDelegate,
         audioRecorder?.stop()
         isRecording = false
         isTranscribing = true
-        // Model still loading and already announced: keep explaining the wait
-        let keepHUD = modelLoading && loadNoticeShown
+        livePreview.stop()
+        // Keep the HUD up while Whisper works if there is something to show:
+        // the live preview text, or why this transcription is slower
+        let explainLoading = modelLoading && loadNoticeShown
+        let keepHUD = explainLoading || recordingHUD.hasPreview
         stopMeter(hideHUD: !keepHUD)
-        if keepHUD { recordingHUD.showTranscribing(notice: .loadingModel) }
+        if keepHUD { recordingHUD.showTranscribing(notice: explainLoading ? .loadingModel : nil) }
         statusItem.button?.title = "⏳"
         updateStatus("Transcribing...")
         if playSounds { NSSound(named: "Pop")?.play() }