VAPolyMk4 vs Hearing Space
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
VAPolyMk4
This app is a powerful bi-timbral polyphonic synthesizer with advanced features like output morphing and a ring modulator. It offers extensive sound design capabilities with multiple oscillators, filters, and envelopes, and can be used standalone or as an AudioUnit Extension.
- Bi-timbral polyphonic synthesis
- Output morphing and ring modulator
- Multiple oscillators, filters, and envelopes
- Standalone and AudioUnit Extension (AUv3) support
- Built-in effects and piano roll sequencer
- MIDI 2.0 and Ableton Link support
- iCloud Drive for project sharing
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VAPolyMk4 is bi-timbral polyphonic synthesizer, which features output morphing, classic ring modulator and global offset parameter control. Each synthesizer consists of three oscillators, resonant low pass and hight pass filter, amplifier, three envelope generators and two LFO. Two synthesizers can be configured as layer or split. VAPolyMk4 operates as a stand alone or as an AudioUnit Extension (AUv3) for iPhone, iPad and Mac. Stand Alone supports Ableton Link, MIDI and audio file export. Built-in Effects include delay, chorus, flanger, reverb, eq and compressor. Project files can be saved in iCloud Drive, so that the project can be accessed from iPhone, iPad or Mac. Main Features Bi-timbral Polyphonic Synthesizer. Output morphing. Classic Ring Modulator. Global Offset Parameter Control. Three oscillators featuring hard sync and through zero FM. Maximum 8 voice polyphony. it depends on performance of the device it is running. Built-in effects and piano roll sequencer. Audio Export. Linear PCM format (AIFF, WAV and CAF) and compressed format (AAC) Support Audio Unit Extension (AUv3). Support MIDI 2.0. Support Foot Pedal and Per Note Control. Support Ableton Link, Bluetooth MIDI, MIDI In / Out. Works on iPhone, iPad and Mac. Support iCloud Drive to share project files between the platforms. Full Factory Preset: 230, Synth CH: 160, Effect: 40 Improvements Support MIDI Foot Pedal (CC#11, CC#64) Support MIDI2.0 Per Note Control Messages MIDI CC Settings are saved. It will be recovered when the app launched in the next time. UI Color can be selected from black, navy or gray. System Requirements iOS 17.0 or later Devices with Apple Silicon are recommended. A13 Fusion or above is highly recommended. if sound is distorted when using a device with less CPU power, reduce number of voices. AudioUnit Extension (AUv3) requires host application which support AudioUnit Extension. AudioUnit Extension is supported by Apple Logic and Apple Garage Band on iOS and macOS. For any other DAW, it depends on the application and some of them don’t support AudioUnit Extension.
Hearing Space
This experimental art application uses AI and machine vision to analyze images, inferring spatial depth and structure. It then transforms these spatial relationships into interactive soundscapes, allowing users to explore a non-human model of space through touch. The app treats your device as a perceptual instrument to reveal AI's internal logic.
- AI-based image analysis
- Machine vision for spatial inference
- Interactive sound generation
- Touch-based sonic exploration
- Perceptual instrument interface
- Artistic and exploratory experience
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Hearing Space-Time is an experimental art application that explores how artificial intelligence perceives space and transforms it into sound. Using machine vision, the app analyzes images to infer spatial depth and structure. These inferred spatial relationships are translated into sound, allowing users to interact with and listen to a non-human model of space. By touching different areas of an image, users activate sonic responses shaped by the machine’s interpretation rather than by visual representation alone. The app treats the mobile device as a perceptual instrument rather than a passive screen. Sound becomes a medium through which machine vision’s internal logic is revealed, inviting reflection on the relationship between human perception, algorithmic interpretation, and spatial understanding. Hearing Space-Time is designed as an artistic and exploratory experience. It does not aim to simulate reality, but to expose how artificial intelligence reconstructs and reorganizes the world through inference. AI-based image analysis using machine vision Interactive sound generation based on inferred spatial depth Touch-based exploration of image-derived sonic space A minimal, contemplative interface designed for artistic engagement
Screenshots
Verdict
The clearest difference is price: Hearing Space at Free against VAPolyMk4's $14.99. Hearing Space also leads on update cadence (every 4 days vs every 2 months). VAPolyMk4's advantage is rating (5.0 vs 4.7). On ratings volume, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Hearing Space is free to download; VAPolyMk4 costs $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.
VAPolyMk4 holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 2 and 3 respectively.
VAPolyMk4 ships an update every 2 months, Hearing Space every 4 days. Both last shipped on October 24, 2026.
| Parameter | VAPolyMk4 | Hearing Space |
|---|---|---|
| Price | $14.99 | Free — better |
| Rating | 5.0 (2 ratings) — better | 4.7 (3 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 2 | 3 — better |
| Update frequency | Every 2 months | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 16.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 20 MB | 261 MB |
| Age rating | 4+ | 4+ |
| Developer | Ryo Togawa | Jing Dong |
Customer experience
VAPolyMk4
Hearing Space
In-app purchases
VAPolyMk4
No in-app purchases
Hearing Space
No in-app purchases









