# OpeNoise vs Signals Generator

The clearest difference is rating: Signals Generator at 4.7 against OpeNoise's 4.0. Signals Generator also leads on ratings volume (29 vs 4). OpeNoise's advantage is in-app purchases (none vs 14) and update cadence (every 7 months vs every 33 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Signals Generator sells 14 one-off in-app purchases. OpeNoise asks for nothing beyond the download.

Signals Generator holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Signals Generator has 29 ratings behind it against 4, so its average is the more settled of the two. Written reviews complicate that: 86% of OpeNoise's written reviews are positive against 67% of Signals Generator's, so the app with the better star average is not the one people write more warmly about.

OpeNoise ships an update every 7 months, Signals Generator every 33 months. The most recent releases landed on October 13, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | OpeNoise | Signals Generator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.0 (4 ratings)](https://appshunter.io/ios/app/openoise/id1387499991/reviews) | **[4.7 (29 ratings)](https://appshunter.io/ios/app/signals-generator/id1526653387/reviews)** |
| Number of ratings | 4 | **29** |
| Positive reviews | **85.7% of reviews** | 66.7% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 7 months** | Every 33 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 12 MB | 15 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Agenzia Regionale per la Protezione Ambientale del Piemonte](https://appshunter.io/developer/1317255035) | [怀卫 张](https://appshunter.io/developer/1252544375) |

## What reviewers say

### OpeNoise

[App page](https://appshunter.io/ios/app/openoise/id1387499991)

This application measures real-time sound pressure levels, displaying minimum and maximum values. It offers advanced analysis like third octave and FFT, with options to save data, calibrate, and share measurements with a community. Note: it is not intended for professional use.

**Highlights:** Real-time A-weighted sound pressure level measurement, Minimum and maximum level tracking, Third octave and FFT analysis, Data saving in text file, Calibration functionality, Measurements displayed on a map, Community sharing of calibration and measurements

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Signals Generator

[App page](https://appshunter.io/ios/app/signals-generator/id1526653387)

Transform your mobile device into a dual-channel signal generator for sound and audio electric signals. Offers a wide variety of waveform types and customizable parameters like amplitude, frequency, and phase. Ideal for professionals and hobbyists for signal generation and circuit measurement.

**Highlights:** Dual-channel signal generation, Multiple waveform types, Adjustable amplitude, frequency, and phase, Independent channel control, Zoomable waveform display, Interface color selection

**Features:** Vision Pro support

**In-app purchases (14)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sine Wave | $0.99 | one-time |
| Square Wave | $0.99 | one-time |
| Gaussian Noise | $0.99 | one-time |
| Uniformly distributed noise | $0.99 | one-time |
| Pink Noise | $0.99 | one-time |
| Red (brown) noise | $0.99 | one-time |
| Maximum Length Sequence | $0.99 | one-time |
| Rayleigh Noise | $0.99 | one-time |
| Sawtooth Wave | $0.99 | one-time |
| Gamma Noise | $0.99 | one-time |
| Functional Wave | $2.99 | one-time |
| Sweep Signal | $2.99 | one-time |
| All Noise Signals | $3.99 | one-time |
| All type of signals | $7.99 | one-time |


## Frequently asked questions

### Is OpeNoise free?

OpeNoise is free to download, with no in-app purchases.

### Is Signals Generator free?

Signals Generator is free to download, with in-app purchases available.

### Which has better reviews, OpeNoise or Signals Generator?

Signals Generator is rated higher. OpeNoise averages 4.0 out of 5 from 4 ratings, while Signals Generator averages 4.7 from 29 ratings.

### Do OpeNoise or Signals Generator have ads?

Neither OpeNoise nor Signals Generator shows ads.

### Which is updated more often, OpeNoise or Signals Generator?

OpeNoise ships an update every 7 months, and Signals Generator every 33 months. Most recently, OpeNoise was updated on October 13, 2026 and Signals Generator on October 7, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*