# HSADSP.31 vs Decibel Meter

The clearest difference is in-app purchases: HSADSP.31 at none against Decibel Meter's 4. HSADSP.31 also leads on ads (none vs shown) and device support (3 vs 1). Decibel Meter's advantage is update cadence (every 4 weeks vs every 3 months). On price there is nothing between them.

Both are free to download. Decibel Meter sells 4 in-app purchases, starting at $4.99 per month. HSADSP.31 asks for nothing beyond the download.

HSADSP.31 ships an update every 3 months, Decibel Meter every 4 weeks. The most recent releases landed on November 6, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | HSADSP.31 | Decibel Meter |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | **Every 4 weeks** |
| Size | 13 MB | 14 MB |
| Requires iOS | **8.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [杏生 卢](https://appshunter.io/developer/1094592555) | [Nico Schroeder](https://appshunter.io/developer/432790036) |

## What reviewers say

### HSADSP.31

[App page](https://appshunter.io/ios/app/hsadsp31/id1453655012)

**Features:** macOS Compatibility

**In-app purchases:** none


### Decibel Meter

[App page](https://appshunter.io/ios/app/decibel-meter-noise-analyzer/id6747433637)

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| One Month Premium | $4.99 | per month |
| One Week Premium | $5.99 | per 7 days |
| One Year Premium | $19.99 | per year |
| Lifetime Premium | $29.99 | one-time |


## Frequently asked questions

### Is HSADSP.31 free?

HSADSP.31 is free to download, with no in-app purchases.

### Is Decibel Meter free?

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

### Do HSADSP.31 or Decibel Meter have ads?

Decibel Meter shows ads; HSADSP.31 does not.

### Which is updated more often, HSADSP.31 or Decibel Meter?

HSADSP.31 ships an update every 3 months, and Decibel Meter every 4 weeks. Most recently, HSADSP.31 was updated on November 6, 2026 and Decibel Meter on October 28, 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.*