# INFINITE SWEEP SYNTH — 無限音階

> App for creating and experiencing auditory illusions like the Infinite Continuous Scale. (iPhone/iPad app by Nobuhiro Takata.)

- Source: https://appshunter.io/ios/app/infinite-sweep-synth/id1515611452 (this page in markdown: same URL + `.md`)
- Developer: [Nobuhiro Takata](https://appshunter.io/developer/1514965382)
- Category: Music, Music, Entertainment
- Price: $4.99
- Rating: 5.00/5 from 3 App Store ratings · 3 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.4 · 28 MB
- Languages: American English, Japanese
- Released: 2020-06-02
- Data updated: 2026-06-10
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/infinite-sweep-synth/id1515611452/reviews.md

## What is INFINITE SWEEP SYNTH?

-Experience the "illusion"-

There are many visual "optical illusion" works, but it is hard to experience the  "auditory illusion".
"INFINITE SWEEP SYNTHESIZER" (hereinafter "INFINITE SWEEP") is an application that can easily reproduce "Infinite Continuous Scale" which is one of "illusions" and create various sounds.
Recommended for live music, recording, meditation, etc.

[What is "Infinite Continuous Scale" ?]

The frequency of sound that can be recognized by humans is said to be approximately 20Hz to 20,000Hz (20kHz).

Also, the sound that a person recognizes is recognized as "the same sound one octave above the original sound" when the frequency doubles.
For example, when the 440Hz sound (A) becomes 880Hz, it becomes "1 octave higher sound (A)".

The Infinite Continuous Scale was discovered by US cognitive scientist Dr. Roger Shepard as an “acoustic illusion” that utilizes these properties.
The Infinite Continuous Scale was named by him as "Shepard tone".

After that, various researchers and artists announced variations of Infinite Continuous Scale.
However, they all needed to be made in a recording studio, or have a special music production environment and equipment.

[Easy infinite scale and new experience]
There are many things that you can experience a mysterious sensation by visual illusion, but We developed this "INFINITE SWEEP" because We wanted to experience the  Infinite Continuous Scale, 
more easily.

[function]
"INFINITE SWEEP" has preset tones, so you can immediately enjoy various infinite scales.

"PLAY / STOP button"
It is a big button that stands out most. If you press this, the infinite scale starts immediately.

"FREEZE button"
This is a "freeze" button that cannot be reproduced with sampled or recorded infinite scale sounds.
You can freeze it at any position, or you can freeze it at a specified pitch.

"Speed ​​volume"
The speed of the infinite scale can be changed.
If it's too early, it may sound like a siren.
The numerical value that can be set with the speed volume sets the time for which the pitch rises one octave.
It is recommended that you set it slowly and change it over 20 to 30 seconds.

"Step Volume"
It has a continuous and smooth pitch change, but you can also listen to it in a staircase scale.
The pitch changes with the step set by the speed volume divided by the number set by this step volume.
You can also try other strange scales (eg 21 scale, etc.) other than the familiar "12 scale".

"UP / DOWN button"
You can switch between rising and falling of the infinite scale.

"Accelerometer mode"
You can switch to "accelerometer mode" from the "red-blue-green" arrow button at the top right of the screen.
By tilting your device, you can control the speed of an infinite scale, and if you hold it upside down, you can descend.
It is to be usable even for a bitly performance.

[Pursuit of Infinite Continuous Scale]
If you are familiar with synthesizers, you can dig deeper to create finer sounds.
INFINITE SWEEP uses 32 oscillators.
Main oscillator group (16 oscillators) called "main sweep generator",
It consists of a "reverse sweep generator" (16 oscillators) that operates in the opposite direction.

The main sweep generator is
・ Basic oscillator waveform change (BASIC / FM)
・ Subharmonic setting (0 to 11 semitones)
・ Low-pass filter
・ Flanger
・ Delay
・ Auto pan
・ Reverb
It is possible to make sounds and adjust effects.

(The basic waveform of the reverse sweep generator is fixed to a sine wave)

[Control via Bluetooth MIDI]

If you have a Bluetooth MIDI compatible keyboard or adapter, an application that can output MIDI via smartphone Bluetooth,
You can control "INFINITE SWEEP" from them.
It is also possible to specify the "start note" that was difficult to capture on the main unit due to the user interface.
It can be used for live performances and recordings.

## Key features

- Infinite Continuous Scale generation
- Adjustable speed and step volume
- UP/DOWN pitch control
- Freeze function
- Accelerometer control mode
- Preset tones

## Recent user reviews (3 of 3)

All indexed reviews: https://appshunter.io/ios/app/infinite-sweep-synth/id1515611452/reviews.md

### 5/5 — Too good!

*2021-08-06, version 1.0.2*

Shepard tones are a little bit better than music I like them, thanks a lot.

### 5/5 — Midi works great as well

*2021-07-24, version 1.0.2*

So hardare midi works straight away. This delivers the amazing infinite tone with a few classic bells amd whisltes

### 5/5 — Unique Synth worth the purchase.

*2020-06-04, version 1.0*

Amazing! Missing ONE thing though... AUv3 please! 😅 hope to see updates in the future.

## Frequently asked questions about INFINITE SWEEP SYNTH

### What is the Infinite Sweep Synth?

Infinite Sweep Synth is a music application that allows users to easily create and experience the "Infinite Continuous Scale," also known as the Shepard tone. It provides controls to manipulate the scale's pitch, speed, and other parameters for unique sound generation.

### What is an Infinite Continuous Scale (Shepard tone)?

An Infinite Continuous Scale, or Shepard tone, is an auditory illusion discovered by Dr. Roger Shepard. It utilizes the properties of sound frequency and octaves to create a tone that seems to continuously rise or fall in pitch without ever reaching a true end.

### What devices is Infinite Sweep Synth compatible with?

Infinite Sweep Synth is compatible with iPhone, iPad, and iPod devices. It is designed to run on Apple's mobile operating system.

### How much does Infinite Sweep Synth cost?

Infinite Sweep Synth is a paid application and costs $4.99. This one-time purchase grants you access to all of its features.

### Can I control the pitch and speed of the Infinite Sweep Synth?

Yes, Infinite Sweep Synth offers "Speed Volume" to adjust the rate of the scale's pitch change and "Step Volume" to alter the pitch change intervals. You can also use the "UP / DOWN button" to switch between rising and falling scales.

### Does Infinite Sweep Synth have ads?

Infinite Sweep Synth does not contain advertisements. As a paid application, it provides an uninterrupted user experience.

### How often is Infinite Sweep Synth updated?

Infinite Sweep Synth was last updated on January 11, 2021, with version 1.0.2. While updates may not be frequent, the app is stable and functional.

### What is the age rating for Infinite Sweep Synth?

Infinite Sweep Synth has an age rating of 4+. This indicates it is suitable for users of all ages and does not contain mature content.

## Version history (last 3 releases)

### 1.0.2 — 2021-01-11

The sound engine has been updated.
There are no UI operational changes.

### 1.0.1 — 2020-06-08

・User interface color adjustment.
・Added link to Movie Tutorial in Help.

### 1.0 — 2020-06-02

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*