# SPLnFFT Noise Meter vs HemiSync

The clearest difference is price: HemiSync at Free against SPLnFFT Noise Meter's $3.99. HemiSync also leads on review sentiment (100% vs 90%). SPLnFFT Noise Meter's advantage is rating (4.8 vs 4.2) and ratings volume (60 vs 9). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

HemiSync is free to download; SPLnFFT Noise Meter costs $3.99 up front. SPLnFFT Noise Meter sells 1 one-off in-app purchase and HemiSync sells 1 in-app purchase, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

SPLnFFT Noise Meter holds the better App Store score, 4.8 against 4.2. That said, the two scores are not equally well evidenced: SPLnFFT Noise Meter has 60 ratings behind it against 9, so its average is the more settled of the two. Written reviews complicate that: 90% of SPLnFFT Noise Meter's written reviews are positive against 100% of HemiSync's, so the app with the better star average is not the one people write more warmly about.

SPLnFFT Noise Meter ships an update every 2 months, HemiSync every 5 weeks. The most recent releases landed on September 24, 2026 and August 29, 2026 respectively.

## The numbers

| Metric | SPLnFFT Noise Meter | HemiSync |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | **[4.8 (60 ratings)](https://appshunter.io/ios/app/splnfft-noise-meter/id355396114/reviews)** | [4.2 (9 ratings)](https://appshunter.io/ios/app/hemisync/id6751762821/reviews) |
| Number of ratings | **60** | 9 |
| Positive reviews | 90.4% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 4 MB | 61 MB |
| Requires iOS | **15.2** | 18.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Fabien Lefebvre](https://appshunter.io/developer/338004167) | [EngineZero](https://appshunter.io/developer/1573141529) |

## What reviewers say

### SPLnFFT Noise Meter

[App page](https://appshunter.io/ios/app/splnfft-noise-meter/id355396114)

This app provides advanced audio measurement capabilities, including sound level metering, frequency analysis, and signal generation. It offers both simple interfaces for daily use and detailed metrics for professional applications, with features compliant with industry standards.

**Highlights:** Sound level meter (noise meter), Frequency analyzer, Frequency meter, Test signal generator, Dosimeter, Leq, peak, L10, L95 measurements, Real-time FFT analysis

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Export raw data to Dropbox + PRO features | $4.99 | one-time |

**What reviewers like**

- ⭐ Highly accurate sound measurements compared to professional equipment
- 🎯 Professional-grade features at affordable price point
- 📊 Comprehensive FFT and frequency analysis capabilities
- 🎨 Clean, intuitive, and visually appealing interface
- 🔧 Multiple weighting options (A, B, C, ISO-498) and response times

**What reviewers complain about**

- 🎤 Microphone gain stuck on auto with built-in iPhone mic
- 📞 Limited customer support accessibility (Facebook-only contact)
- 🔄 Persistent review request pop-ups despite already reviewing
- 📱 Display text sizing issues on some devices (iPhone 11)
- 🌐 No website or email support outside of Facebook

**Reported bugs**

- Microphone gain slider unresponsive/locked on auto
- Landscape mode gets stuck, preventing setting changes
- Text display cropped on iPhone 11 (showing '10...' instead of '100.1')
- App freezes and requires reboot on some devices
- Review request pop-up appears repeatedly even after review submitted

**Requested features**

- Ability to override automatic microphone gain control
- Recording functionality with audio and dB level overlay
- Landscape mode support with full FFT display
- Extended frequency range (down to 20Hz for 3rd octave analysis)
- Microphone frequency calibration curve adjustment


### HemiSync

[App page](https://appshunter.io/ios/app/hemisync/id6751762821)

This app generates binaural beats and isochronic tones to aid in meditation and relaxation. Explore various sound frequencies and pre-set combinations for personal wellness routines, with customizable timers and controls.

**Highlights:** Binaural beat and isochronic tone generation, Customizable frequency ranges (Delta, Theta, Alpha, Beta, Gamma), Pre-configured audio presets, Session timer functionality, Solfeggio frequency options

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $0.99 | per month |


## Frequently asked questions

### Is SPLnFFT Noise Meter free?

SPLnFFT Noise Meter costs $3.99, and also offers in-app purchases.

### Is HemiSync free?

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

### Which has better reviews, SPLnFFT Noise Meter or HemiSync?

SPLnFFT Noise Meter is rated higher. SPLnFFT Noise Meter averages 4.8 out of 5 from 60 ratings, while HemiSync averages 4.2 from 9 ratings.

### Do SPLnFFT Noise Meter or HemiSync have ads?

Neither SPLnFFT Noise Meter nor HemiSync shows ads.

### Which is updated more often, SPLnFFT Noise Meter or HemiSync?

SPLnFFT Noise Meter ships an update every 2 months, and HemiSync every 5 weeks. Most recently, SPLnFFT Noise Meter was updated on September 24, 2026 and HemiSync on August 29, 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.*