# Sound Level & Spectrogram

> iPhone sound level meter with real-time spectrogram and advanced acoustic analysis. (iPhone/iPad app by TOON,LLC.)

- Source: https://appshunter.io/ios/app/sound-level-and-spectrogram/id6503722682 (this page in markdown: same URL + `.md`)
- Developer: [TOON,LLC](https://appshunter.io/developer/633948723)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 18.7 · 4 MB
- Languages: American English
- Released: 2024-06-10
- Data updated: 2026-08-13
- Monetization: ad-supported
- User reviews in markdown: https://appshunter.io/ios/app/sound-level-and-spectrogram/id6503722682/reviews.md

## What is Sound Level & Spectrogram?

"Sound Level & Spectrogram" is a sound level meter app for iPhone to easily measure the sound level of noise and music in your living environment. 

Simply tap the start button to measure sound levels in decibels (dB) and view the real-time variation of the sound level. You can also use the spectrogram feature to visually check the frequency characteristics of the sound source.

Furthermore, you can select between frequency weighting correction characteristics and time weighting characteristics, which are essential for standard sound level meters, enabling appropriate sound measurement.

Exposure to noise can impact health, potentially causing tinnitus, sleep disorders, stress, cognitive decline and heart disease. These risks have also been highlighted by the World Health Organization (WHO).

Understanding noise levels is the first step towards improving your quality of life. Use this app to protect your health and create a comfortable living environment.

Features:
- Sound level measurement (dB): Leq (equivalent sound level), Min (minimum value), Max (maximum value), Avg (time-averaged equivalent sound level)
- Frequency weighting correction characteristics: A (general sound level measurement with auditory correction), C (sound level measurement with almost flatter correction than A correction, e.g. peak evaluation at high volume), Z (flat characteristics without auditory correction, physical sound level measurement) 
- Time weighting characteristics: Fast=0.125sec, Slow=1.0sec
- Time course graph
- Spectrogram: 1/3 octave band analysis
- Measurement time: 20 sec

Applications:
- Environmental noise measurement
- Architectural acoustics 
- Live sound check
- Installation of audio equipment 
- Tuning of sound equipment
- Device management

Example of the noise level situation: 
 - 130 dB: Engine sound of Airplane
 - 110 dB: Horn of Car
 - 100 dB: Noise of passing train
 - 90 dB: In loud factory
 - 80 dB: In the train, Vacuum cleaner
 - 70 dB: Noisy office, Noisy Street
 - 60 dB: Quiet Car, Normal conversation
 - 50 dB: Quiet office
 - 40 dB: In the library, Quiet residential area
 - 30 dB: Outskirts of midnight, Whisper
 - 20 dB: Sounds of rubbing leaves

Note:
- Spectrogram is a tool to analyze the frequency spectrum of sound, with time on the horizontal axis, frequency on the vertical axis, and the strength of the signal represented by colors, and is used for acoustic analysis, voiceprint identification, etc.
- This app is adjusted the reference value for iPhone. However, the built-in microphone of your iPhone is likely to have a non-uniform gain. Therefore, exact measurements are not guaranteed.
- The standard noise measurement range is 30-130 dBA, and the measured value (Leq) is about 30 dBA in a quiet room of the household. Due to the presence of background noise, noise levels are never measured at 0dBA even in very quiet environments. In a typical anechoic room, the noise level is around 5-15 dBA.
- At the initial startup after installing the app, the iOS system asks for permission to access the built-in microphone. In this case, you need to enable access to the microphone. If you have not enabled this setting, this app cannot work by privacy restrictions of the iOS system. Please enable the access permission on the iOS setting, "Settings > Privacy & Security > Microphone".

Please visit our iOS app support page for more information on this app.

## Key features

- Sound level measurement (dB)
- Real-time spectrogram analysis
- Frequency weighting correction (A, C, Z)
- Time weighting characteristics (Fast, Slow)
- Time course graph
- Environmental noise measurement

## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/sound-level-and-spectrogram/id6503722682/reviews.md

### 5/5 — さすが日本製

*2024-08-10*

これです！
欲しかったの！
使いやすいしわかりやすい！

ケチのつけようが無い。あえて言えばクリアボタンがあってもいいかな〜ってとこくらいデス。

## Frequently asked questions about Sound Level & Spectrogram

### What is Sound Level & Spectrogram used for?

Sound Level & Spectrogram is used to measure sound levels in decibels (dB) and visualize the frequency characteristics of sound sources using a spectrogram. It helps users understand noise levels in their environment for health and quality of life improvements.

### Does Sound Level & Spectrogram have ads?

Yes, Sound Level & Spectrogram contains advertisements. As it is a free application, ads are displayed to support its development and maintenance.

### What devices is Sound Level & Spectrogram available on?

Sound Level & Spectrogram is currently available for iPhone. It is designed to work on Apple's mobile operating system.

### How accurate are the measurements from Sound Level & Spectrogram?

While the app is adjusted for iPhone, the built-in microphone's gain can be non-uniform, meaning exact measurements are not guaranteed. The standard noise measurement range is 30-130 dBA.

### What are the frequency and time weighting options in Sound Level & Spectrogram?

Sound Level & Spectrogram offers frequency weighting correction (A, C, Z) for different measurement types and time weighting characteristics (Fast=0.125sec, Slow=1.0sec) to capture sound dynamics appropriately.

### How often is Sound Level & Spectrogram updated?

The app was last updated on October 10, 2025, with version 3.0. This indicates a recent update, suggesting ongoing development and support from the developer.

### What is the age rating for Sound Level & Spectrogram?

Sound Level & Spectrogram has an age rating of 4+. This means it is considered suitable for children aged 4 and above, with no mature content.

### Can Sound Level & Spectrogram be used for professional acoustic analysis?

Yes, with features like frequency and time weighting, and a spectrogram for 1/3 octave band analysis, it can be used for applications such as environmental noise measurement, architectural acoustics, and live sound checks.

## Version history (last 4 releases)

### 3.0 — 2025-10-10

- Minor improvements.
- Requires iOS 18.7 or later.

### 2.1 — 2025-06-10

- Minor improvements.
- Renewed icon design.
- Requires iOS 18.5 or later.

### 2.0 — 2025-01-21

- Changed App name.
- Renewed UI design.
- Requires iOS 18.2 or later.

### 1.0 — 2024-07-02

No release notes.

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## More apps by TOON,LLC

- [Audio Tone Generator Lite](https://appshunter.io/ios/app/audio-tone-generator-lite/id633948720)
- [Audio Frequency Analyzer](https://appshunter.io/ios/app/audio-frequency-analyzer/id684641742)
- [Sound Level Analyzer Lite](https://appshunter.io/ios/app/sound-level-analyzer-lite/id886090835)
- [Sound Level Analyzer](https://appshunter.io/ios/app/sound-level-analyzer/id886109671)
- [Hearing Analyzer Portrait](https://appshunter.io/ios/app/hearing-analyzer-portrait/id922806926)
- [Hearing Analyzer Lite](https://appshunter.io/ios/app/hearing-analyzer-lite/id922827806)

All apps by TOON,LLC: https://appshunter.io/developer/633948723

## Related topics

[sound level](https://appshunter.io/ios/topics/sound-level)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-13.*