# Decibel X vs Audio Function Generator

The clearest difference is ratings volume: Decibel X at 162K against Audio Function Generator's 2.2K. Audio Function Generator's advantage is review sentiment (77% vs 61%) and update cadence (every 6 weeks vs every 3 months). On price, rating, ads and in-app purchases there is nothing between them.

Both are free to download. Decibel X sells 5 in-app purchases, starting at $1.99 per 7 days and Audio Function Generator sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

On the App Store both sit at effectively the same score — 4.6 for Decibel X against 4.7 for Audio Function Generator. That said, the two scores are not equally well evidenced: Decibel X has 162K ratings behind it against 2.2K, so its average is the more settled of the two. Written reviews are what separate them: 61% of Decibel X's written reviews are positive against 77% of Audio Function Generator's.

Decibel X ships an update every 3 months, Audio Function Generator every 6 weeks. The most recent releases landed on September 26, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Decibel X | Audio Function Generator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (162K ratings)](https://appshunter.io/ios/app/decibel-xdb-sound-level-meter/id448155923/reviews) | **[4.7 (2.2K ratings)](https://appshunter.io/ios/app/audio-function-generator/id768229610/reviews)** |
| Number of ratings | **162K** | 2.2K |
| Positive reviews | 61.3% of reviews | **77.1% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 6 weeks** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 90 MB | 14 MB |
| Requires iOS | 17.0 | **15.5** |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SkyPaw Co., Limited](https://appshunter.io/developer/1842040687) | [Thomas Gruber](https://appshunter.io/developer/342699861) |

## What reviewers say

### Decibel X

[App page](https://appshunter.io/ios/app/decibel-xdb-sound-level-meter/id448155923)

This app transforms your device into a professional sound level meter, precisely measuring ambient noise pressure. It offers advanced features like frequency analysis, historical data management, and dosimeter functions, making it useful for various applications and entertainment.

**Highlights:** Precise sound pressure level measurement, Frequency spectrum analysis (FFT, BAR graphs), Historical data recording and export, Dosimeter with NIOSH, OSHA standards, Apple Watch and Health App integration, Customizable calibration and filters

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Membership | $1.99 | per 7 days |
| Monthly Membership | $5.99 | per month |
| Annual Membership | $49.99 | per year |
| ITU-R 468, A, B, C Weightings | $1.99 | one-time |
| Data Export | $2.99 | one-time |

**What reviewers like**

- ⭐ Excellent app
- 👍 Easy to use and understand
- 🔍 Useful for various applications
- 🎓 Helpful for hearing protection
- 🔧 Accurate and reliable

**What reviewers complain about**

- 💰 Expensive subscription model
- 🔒 Misleading free trial
- 📢 Intrusive ads
- 🤖 Inaccurate readings compared to professional meters
- 🤔 Confusing interface

**Reported bugs**

- App crashes when deleting recordings
- Microphone issues on certain devices
- Saved files not accessible after updates

**Requested features**

- Add GPS coordinates to recordings
- Improve reporting and data export
- Provide more weighting options
- Extend frequency range
- Allow music playback while using the app


### Audio Function Generator

[App page](https://appshunter.io/ios/app/audio-function-generator/id768229610)

Generate various audio test tones, including sine, square, triangle, and sawtooth waves. Explore frequency and volume sweeps, noise generation, and custom preset creation. Advanced features like extended frequency ranges and multi-tone playback are available with an upgrade.

**Highlights:** Generate sine, square, triangle, and sawtooth tones, Frequency and volume sweep generation, Noise generation (white, pink, violet, etc.), Custom preset creation and saving, Extended frequency range (PRO feature), Multi-tone playback (PRO feature)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade to PRO | $9.99 | one-time |

**What reviewers like**

- 👍 Great app
- 🎶 Helps with Tinnitus
- 💯 Best app I've paid for
- 🔍 Highly recommended
- 🎨 Attention to detail

**What reviewers complain about**

- 🐛 Crashes
- 💰 Deceptive/Money hungry
- 🔒 Basic features paywalled
- 🔒 Limited without paying
- 🔒 Removed functionality to push paid version

**Reported bugs**

- Crashes on launch
- Volume slider issues
- Airplay not working
- Sound distortion when display is active

**Requested features**

- Add download/save feature for custom sounds
- Improve sweep function (continuous mode, better frequency control)
- Add more multi-frequency rows
- Implement 432Hz base frequency option
- Add phase control for noise generators


## Frequently asked questions

### Is Decibel X free?

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

### Is Audio Function Generator free?

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

### Which has better reviews, Decibel X or Audio Function Generator?

Audio Function Generator is rated higher. Decibel X averages 4.6 out of 5 from 162K ratings, while Audio Function Generator averages 4.7 from 2.2K ratings.

### Do Decibel X or Audio Function Generator have ads?

Neither Decibel X nor Audio Function Generator shows ads.

### Which is updated more often, Decibel X or Audio Function Generator?

Decibel X ships an update every 3 months, and Audio Function Generator every 6 weeks. Most recently, Decibel X was updated on September 26, 2026 and Audio Function Generator on September 24, 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.*