Privacy Policy
Last updated: October 26, 2026
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This Privacy Policy applies to all tools on the ML Music Studio website, as well as the iOS/iPadOS/macOS/visionOS apps AudioEngineerToolkit, AET Quiz, Stage Sound Certification Prep, AudioEngineer Ear Trainer, AudioEngineerKit: SPL & RTA, DAW Shortcuts — KeyMap, Patch & I/O, and TempoScope.
AudioEngineerToolkit App
The app runs entirely on-device with no internet connection required. It does not use account sign-up, server communication, analytics tools, or ad SDKs, and it does not collect, store, or transmit any personal information or usage data. It does not request device permissions such as location, microphone, camera, or contacts.
AET Quiz App
A free app containing just the practice quiz feature from AudioEngineerToolkit. It likewise runs entirely on-device with no internet connection, and does not use account sign-up, server communication, analytics tools, or ad SDKs. It does not collect, store, or transmit any personal information or usage data, and does not request device permissions.
Stage Sound Certification Prep App
A quiz app to prepare for the Korean Stage Arts Professional (Sound) Level 1–3 certification written exam. Quizzes run on-device without an internet connection; there is no account sign-up and no analytics tools or ad SDKs. Server communication is limited to the purchase verification below and checking for question/explanation content updates (Expo EAS Update — only app version and platform are sent, no personal data). Quiz progress (correct/incorrect answers, completion status) is stored only on-device and never transmitted externally. For in-app purchase (lifetime unlock) payment processing, it uses RevenueCat (revenuecat.com), which sends an anonymous user identifier and purchase receipt information to Apple or Google Play and RevenueCat servers solely to verify the purchase. No personally identifiable information such as name or email is collected, and it does not request device permissions such as location, microphone, camera, or contacts.
AudioEngineerKit: SPL & RTA App
A collection of audio measurement tools including an SPL meter, real-time spectrum analyzer (RTA), LUFS, RT60, and a delay finder. It runs entirely on-device with no internet connection required, and does not use account sign-up, server communication, analytics tools, or ad SDKs. It requests microphone access for real-time measurement; the audio signal is processed only on-device and is never recorded or transmitted externally. Settings such as calibration values are stored only on-device. Payment for the Pro feature (a one-time, lifetime in-app purchase) is handled entirely through Apple's StoreKit — we never collect payment methods or card information. No personally identifiable information such as name or email is collected, and it does not request device permissions such as location, camera, or contacts. From version 1.2, the app may ask for notification permission for background measurement and feedback-monitoring alerts; notifications are created on the device and nothing is sent out. Sound-check lists (frequencies and venue names) are stored only on the device. Noise-source classification (AI) runs only on the device, and no audio is sent out.
AudioEngineer Ear Trainer App
An ear-training app for frequency perception (pink-noise EQ boost/cut, 10 bands free and 31 bands with Pro) and audio effects listening (Reverb, Delay, Chorus, and more). It runs entirely on-device with no internet connection required, and does not use account sign-up, server communication, analytics tools, or ad SDKs. Training data such as your best streak is stored only on-device and never transmitted externally. Personal music files imported by Pro users are played and processed only on-device, and are never stored or transmitted externally. Payment for the Pro feature (a one-time, lifetime in-app purchase) is handled entirely through Apple's StoreKit — we never collect payment methods or card information. No personally identifiable information such as name or email is collected, and it does not request device permissions such as location, microphone, camera, or contacts.
DAW Shortcuts — KeyMap App
An app for searching, translating, and drilling keyboard shortcuts across six DAWs. It runs entirely on your device without an internet connection, requires no account, collects no personal information, and uses no analytics or advertising SDKs. To update its shortcut data, the app may anonymously download static files from our content delivery network (CDN); no personally identifiable information is transmitted in this process. Training records (right/wrong answers, day streak, progress) are stored only on your device and are never transmitted. Payment for Pro features (in-app purchase, lifetime unlock) is handled solely through Apple's StoreKit; we never collect payment methods or card details. We do not collect personally identifiable information such as your name or email, and the app requests no device permissions such as location, microphone, camera, or contacts.
Patch & I/O app
How to use it · FAQ · full text →
An app for building input lists, patchbays, signal flow diagrams and stage plots. There is no sign-up, no analytics tool and no ad SDK, and we collect no personally identifying information such as names or email addresses. Your documents are stored on the device; if iCloud is turned on, they sync only between your own devices through Apple’s private iCloud database. That data belongs to your Apple account, we cannot read it, and turning iCloud off stops the sync. PDF/CSV export and label printing happen entirely on the device and leave it only when you choose to share. Payment for the lifetime unlock goes through Apple’s StoreKit only; we never collect payment methods or card details. The app requests no microphone, location, camera or contacts permissions.
Yul app
A gugak tuner and jangdan app. The microphone is used only when you start listening, recording or practice, and audio is used on the device solely to compute pitch. Recordings, practice logs and edited jangdan are stored on the device only and never transmitted. No account, server communication, analytics or advertising SDK; the Lifetime purchase is processed only through Apple StoreKit. See the Yul privacy policy for details.
TempoScope app
An app that detects tempo and key from the microphone in real time, and tempo, key, and chord progressions from audio files. All analysis runs on your device; the app contains no networking code at all. It does not require an account, does not communicate with any server, and uses no analytics tools or advertising SDKs. Microphone permission is requested for live detection and for Record to MIDI (from 1.4, iPhone and iPad). Audio from live detection is used only for on-device analysis and is not stored. In Record to MIDI, only the last recording you start yourself is kept on your device so it can be turned into MIDI; a new recording replaces it, and it is deleted when you delete the app. No audio is ever transmitted. Audio files you choose are likewise processed only on your device. Analysis history is stored only on your device and is removed when you delete it in the app. Payment for Pro features (a one-time lifetime in-app purchase) is handled solely through Apple's StoreKit; we never collect payment methods or card details. We do not collect personally identifiable information such as names or email addresses, and we do not request location, camera, or contacts permissions.
Website Tools (Ear Trainer, Generator, RTA, SPL Meter, etc.)
Most tools run entirely in your browser with no account sign-up or server transmission. RTA and SPL Meter request microphone access for real-time measurement, but the audio signal is processed only on-device (in the browser) and is never recorded or sent to an external server. RTA calibration values are stored only in the browser's localStorage.
Ads and Affiliate Links
This website may include Google AdSense ads and some affiliate links. Advertising partners such as Google may collect information needed for ad personalization, such as cookies, in accordance with their own policies.
Third-Party Sharing
Aside from the advertising and affiliate partners noted above, we do not directly collect any personal information to share with third parties.
Contact
If you have questions about this Privacy Policy, please contact us at wa547@hanmail.net.