OpeNoise vs Signals Generator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OpeNoise
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.
- 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
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OpeNoise is a real-time noise level meter. TECHNICAL SPECIFICATIONS: - Real-time A-weighted sound pressure level measurement - Minimum and maximum level - Third octave and FFT analysis - Data saving in text file - Calibration - Displaying measurements on a map - Metadata compilation - Sharing calibration and measurements with the OpeNoise community TERM OF USE This app is not intended for professional use, it does not necessarily guarantee an accurate noise measurement. Since each device has a different response to noise, a comparison with a professional noise level meter in the measurement dynamic range is required. The utilization of the app requires adequate technical knowledge and skill; an extemporary measurement might not be correct. The calibrations and measurements sent to the OpeNoise community will be used for statistical purposes only and cannot be used in any way to verify compliance with legal limits. CREDITS Developers: Arpa Piemonte (Regional Agency for the Protection of the Environment of Piedmont - Italy - www.arpa.piemonte.it). The code is open source under GNU v.2 license or later, the code is on GitHub: https://github.com/Arpapiemonte/ KEYWORDS noise level meter, level, sound, noise, measure, measurement, dB, db, dBA, dB(A), decibel
Signals Generator
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.
- Dual-channel signal generation
- Multiple waveform types
- Adjustable amplitude, frequency, and phase
- Independent channel control
- Zoomable waveform display
- Interface color selection
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This app transforms your phone into a powerful handheld dual-channel signal generator for generating sound signals (and can also be used by professionals to generate audio electrical signals). Signal types include: sine wave, triangular wave, sawtooth wave, rectangular wave, Gaussian noise, Rayleigh noise, gamma noise, salt-and-pepper noise, uniformly distributed noise, pink noise, red (brown) noise, blue noise, purple noise, longest sequence signal, frequency-sweep signal, elementary function waveform, and hand-drawn waveform. It can switch between single-channel and dual-channel operation; the dual channels can independently set waveforms and their parameters. The parameters of the signal, such as amplitude, frequency, and phase, can be adjusted. The waveform can be scaled freely using gestures or buttons, making it simple and easy to use. Support interface color selection. This application is normally used to generate sound signals and poses no risks. Special instructions for circuit measurement: Professionals can utilize this application for circuit measurements, with audio electrical signals being output through the left and right channels of headphones. Please ensure safety: You must possess sufficient professional knowledge, and isolation equipment must be added to high-voltage circuits. Circuit measurement involves risks. The author of this application will not be responsible for any personal or equipment damage caused by the correct or incorrect use of this application.
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | OpeNoise | Signals Generator |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (4 ratings) | 4.7 (29 ratings) — better |
| Positive reviews | 85.7% of reviews — better | 66.7% of reviews |
| Number of ratings | 4 | 29 — better |
| Update frequency | Every 7 months — better | Every 33 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 15.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 12 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Agenzia Regionale per la Protezione Ambientale del Piemonte | 怀卫 张 |
Customer experience
OpeNoise
Signals Generator
In-app purchases
OpeNoise
No in-app purchases
Signals Generator
- Sine Wave$0.99
- Square Wave$0.99
- Gaussian Noise$0.99
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- Uniformly distributed noise$0.99
- Pink Noise$0.99
- Red (brown) noise$0.99
- Maximum Length Sequence$0.99
- Rayleigh Noise$0.99
- Sawtooth Wave$0.99
- Gamma Noise$0.99
- Functional Wave$2.99
- Sweep Signal$2.99
- All Noise Signals$3.99
- All type of signals$7.99
Questions
Is OpeNoise free?
Is Signals Generator free?
Which has better reviews, OpeNoise or Signals Generator?
Do OpeNoise or Signals Generator have ads?
Which is updated more often, OpeNoise or Signals Generator?
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