Free
About
Generate any sound frequency between 20Hz and 20,000Hz for relaxation, meditation, or testing hearing. Includes a simple instrument tuner and bonus tracks.
✓Generate sound frequencies 20Hz-20,000Hz
✓Test hearing range with slider
✓Built-in simple instrument tuner
✓Supports popular relaxation frequencies (432Hz, 528Hz)
✓Includes bonus audio tracks
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What's New in Otosan
1.6.1
October 29, 2026
■We've renamed the app from "RetroTone" to "Otosan." It's the same app you know — just a new name. ■New: Binaural Beats — plays slightly different frequencies in each ear to help you relax or focus. Choose from Theta(5Hz)/Alpha(10Hz)/Beta(15Hz)/Gamma(40Hz) presets. Launch from the "Binaural" chip at the top (not intended as a medical device; effects are not guaranteed. Headphones recommended). Minor bug fixes and stability improvements.
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FAQ
What is Otosan used for?
Otosan is a utility app that allows you to generate sound frequencies from 20Hz to 20,000Hz. It can be used for relaxation, meditation, studying, sleep, testing your hearing range, and tuning musical instruments.
Does Otosan have ads?
No, Otosan is ad-free, providing an uninterrupted user experience for all its features.
What frequencies can Otosan generate?
Otosan can generate any frequency value between 20Hz and 20,000Hz, offering a wide range for various applications.
Can Otosan be used to tune instruments?
Yes, Otosan includes a built-in tuner that works well for tuning musical instruments.
What devices does Otosan support?
Otosan is currently supported on iPhones.
What is the age rating for Otosan?
Otosan has an age rating of 4+, making it suitable for a wide range of users.
How often is Otosan updated?
The latest version of Otosan is 1.6.1, and it was last updated on October 29, 2026. Updates typically bring improvements and new features.
Does Otosan offer different subscription tiers?
Otosan is a free application and does not offer any subscription tiers or in-app purchases.
