課金なし！で使える高音質ボイスレコーダー

Audio Recorder is a free voice recorder app that allows you to record high-quality audio.
In addition to displaying waveforms, FFTs, and spectrograms while recording,
it also supports offline AI transcription using Whisper/Vosk and video audio extraction.
All features are available without charge, with only ad viewing.

Audio Recorder is a high-quality, free voice recorder app for clear sound recording and visualization.
It features real-time waveform, FFT, and spectrogram display, as well as offline AI transcription with Whisper/Vosk.
All features are available completely free—ad-supported, no subscriptions required.

⸻

🎧 Main Features
• High-Quality Recording
・AAC (.m4a, 64–256 kbps) / WAV (PCM16)
・Mono/stereo, 44.1–192 kHz (auto fallback)
・Silence skip, fade, noise suppression, auto gain
• Supports AAC (.m4a, 64–256 kbps) / WAV (PCM16)
• Mono or stereo recording, 44.1–192 kHz sampling (auto fallback)
• Silence skip, fade in/out, noise suppression, auto gain control
• Visualization Visualization
・Real-time waveform, FFT, and spectrogram display
・Silence gate threshold line and color inversion for gate activity
• Real-time waveform / FFT / spectrogram display
• Threshold line and color inversion for gate activity
• Library Management
・Search, sort, share, rename, and delete recordings
・Extract audio from video/*
• Search, sort, rename, share, and delete recordings
• Extract audio from video files with one tap
• Playback
・Speed ​​adjustment, seek, and loop playback with Media3 player
・Focus monitoring and Bluetooth priority routing
• Playback with seek, loop, and speed control
• Auto Bluetooth routing and focus monitoring
• AI Transcription (Offline)
・In-device conversion with Whisper/Vosk (Japanese/English)
・No external transmission, partial or full results can be shared
• Whisper/Vosk transcription processed entirely offline
• No cloud upload; share partial or full results easily
• Widget Widgets
・Start recording instantly from the home screen or shortcuts
• Start recording instantly from home widgets or shortcuts

⸻

⚙ Settings / Customization

・Save Destination / Filename Prefix
・Output Format (AAC/WAV) and Bitrate Settings
・Noise Suppression, Echo Cancellation, High-Pass (0/60/80/120Hz)
・FFT Smoothing, Buffer Mode, Bluetooth Priority
• Choose save folder and filename prefix
• Adjust format, bitrate, and high-pass filter
• Control FFT smoothing, buffer mode, and Bluetooth priority

⸻

☁ Sharing & Cloud / Sharing & Cloud Export

・Send to LINE, Gmail, Slack, Notion, etc. from the Share Sheet
・Save to a folder, Google Drive, or Dropbox via SAF
• Share via Android Share Sheet (LINE, Gmail, Slack, etc.)
• Export recordings to Google Drive, Dropbox, or any folder

⸻

💡 Price / Pricing

・Fully free (no in-app purchases)
・Ads only, no restrictions
• 100% Free – no in-app purchases
• All features unlocked with minimal ads

⸻

📱 System Requirements

・Android 9 (API 28) or higher
・Sample rate/Bluetooth recording is device-dependent
• Requires Android 9 (API 28) or higher
• Sampling rate and Bluetooth behavior may vary by device

⸻

🔒 Permissions

RECORD_AUDIO: Recording
POST_NOTIFICATIONS: Recording status notification
READ_MEDIA_AUDIO: Saving and sharing
BLUETOOTH_CONNECT: Using an external microphone
READ_PHONE_STATE: Incoming call control
MODIFY_AUDIO_SETTINGS: Routing control
INTERNET/ACCESS_NETWORK_STATE: Ads and cloud connectivity

RECORD_AUDIO – Recording sound
POST_NOTIFICATIONS – show status
READ_MEDIA_AUDIO – save/share recordings
BLUETOOTH_CONNECT – use external mic
READ_PHONE_STATE – manage calls
MODIFY_AUDIO_SETTINGS – audio routing
INTERNET / ACCESS_NETWORK_STATE – ads & cloud

⸻

⚠ Notes

- Recording source and Bluetooth operation may vary depending on the device.
- You can check the status using "Input," "BT:OK/NG," and "Gate" on the recording screen.
- Exclude long-term recordings from power-saving settings.
- Recording data will not be sent externally or saved to a server.
Device-specific differences may apply.
Check "Input", "BT:OK/NG", and "Gate" indicators during recording.
Exclude the app from battery optimization for long sessions.
Your recordings never leave your device.

⸻

🔎 Keywords

Voice recorder, recording app, high-quality audio, transcription, Whisper, Vosk,
Audio extraction, spectrogram, FFT, silence removal, Android recording, free app,
voice recorder, audio recorder, transcription, waveform, spectrogram,
AI speech-to-text, meeting, lecture, podcast, free, offline, high quality

⸻

🔐 Privacy

- All recording data and transcriptions are processed on-device.
- No data is sent or stored on servers.
- The Google Mobile Ads SDK may collect device information necessary for ad delivery.
- Cloud sharing is only performed upon user interaction.
All audio and text are processed locally.
No data sent to servers.
Google Mobile Ads SDK may collect ad-related information. identifiers.
Cloud exports occur only by user action.
Privacy policy: https://cavemen.jp/privacy/audio-recorder