# FreqCheck: See Sound/Vibration — ISO 17025 Certified Analyzer

> ISO 17025 certified frequency analyzer for iPhone/iPad, 1-100 Hz spectrum. (iPhone/iPad app by Abundance Sea, LLC.)

- Source: https://appshunter.io/ios/app/freqcheck-see-soundvibration/id6760624311 (this page in markdown: same URL + `.md`)
- Developer: [Abundance Sea, LLC](https://appshunter.io/developer/1885377023)
- Category: Utilities, Education
- Price: Free with in-app purchases
- Rating: 5.00/5 from 3 App Store ratings
- Age rating: 12+
- Requires: iOS 18.6 · 17 MB
- Languages: American English
- Released: 2026-04-05
- Data updated: 2026-10-24
- Monetization: free with in-app purchases

## What is FreqCheck?

* ISO 17025-calibrated spectral engine
* 0.2 Hz–192 kHz range, 384 kHz sampling
* IEC Z, A & C Frequency Weighting
* Fast / Slow Time Integration (SLM)
* Native Hardware DC Block
* Forensic-sealed, tamper-proof reports
* 100% offline, zero-knowledge privacy

FreqCheck is the first Class 1 Mobile Lab App — an ISO/IEC 17025-calibrated, NIST-traceable spectral engine powered by IND CORE™ (U.S. Patent No. 12,659,418, Patent Pending 19/660,467) that adapts to your expertise.

From 0.2 Hz infrasound to 192 kHz tactical WideBand acoustics — with raw 384.0 kHz sampling. FreqCheck turns your iOS device into an enterprise-grade measurement lab and precision Sound Level Meter (SLM).

See Sound and Vibration. Verify therapeutic audio tracks and mystery hums.

ENTERPRISE METROLOGY, ONE APP 
Everyday scanning, raw Pro Input Mode (PIM), Tactical WideBand Metrology, and Dynamic Pulse Sequence (DPS) — all in one certified engine.
DC-coupled Line-In connects to pro DAQs and instrumentation mics with zero attenuation, scaling from internal mic to 384.0 kHz captures.

PRO INPUT MODE (PIM) 
Direct control over channel selection, sample rate locks, ADC ceilings, and sensor sensitivity (mV/Pa or mV/g) — bypassing auto-gain and filters. Features standard acoustic SLM lenses: toggle Z-Flat, A-Weighted (human hearing/environmental), and C-Weighted (occupational peak) filters, plus Fast (125ms) and Slow (1s) Time Integration averaging.

Switchable Hardware DC Block eliminates electrical offsets from external DC-coupled DAQs while preserving 0.2 Hz infrasound. Presets save hardware profiles and weighting selections for repeatable field precision.

TACTICAL WIDEBAND METROLOGY 
High-frequency acoustic analysis up to 192.0 kHz (384.0 kHz sampling). Dynamic 65,536-point FFT architecture powers enterprise spectral resolution at extreme clock speeds. Includes SPL readouts, live tracking, Peak Hold (Max SPL), and uncompressed telemetry.

DYNAMIC PULSE SEQUENCE (DPS) 
Impulse metrology per MIL-STD-1474E (Z-Flat), OSHA standards (C-Weighted), and comparative suppressor R&D. Isolates and logs extreme peaks via multi-shot logarithmic averaging. Configurable pulse counts (3–10), threshold gates, and lockout windows (0.5–3.0s) deliver exact Peak SPL readings for tactical, industrial, and engineering use.

OFFLINE MEDIA AUDITING 
Import raw video and lossless audio (.wav, .flac, .alac, .aiff, .m4a, .mp3) for offline calibrated analysis — audit media claims, verify sound therapy tracks, and run forensic signal analysis configurable with (PIM).

FORENSIC-GRADE PROOF 
Four-layer security: Metrology Configuration Snapshot (stamping active Z, A, or C weighting and hardware parameters), device-hash anchoring, real-time SHA-256 sealing, and signed PDF Audit Reports. Any tampering breaks the seal. ISO 17025:2017 Calibrated (Cert #05122C9A 2602).

ZERO-KNOWLEDGE PRIVACY 100% local, on-device processing via edge computing. No raw audio/video is ever uploaded or stored. Zero data center dependency.

Starter: Free, ad-supported

*Remove Ads: U$2.99 one-time.

**Pro Monthly: U$19.99/mo, 7-day free trial.

**Pro Lifetime: U$149.99 one-time.

**Pro unlocks the LOGS vault, full PDF Audit Reports, and posting/commenting in the Nyquist Forum.

THE MICROSCOPE MOMENT 
The microscope didn't create bacteria — it revealed what was already there.

GPS didn't create your location — it made it knowable.

FreqCheck makes the full spectrum visible, measurable, and provable.

You don't need a degree. You need one tap.

Privacy Policy: freqcheck.com/privacy.html 
Terms of Use: freqcheck.com/terms.html

DISCLAIMER: 
Metrology tool for research, acoustic consulting, and educational use only. Not for medical diagnosis. Full NIST traceability requires unbroken calibrated external hardware.

LICENSE: 
Valid for technical verification & media analysis. Void for commercial manufacturer certification or packaging claims. © 2025-2026 Abundance Sea, LLC. All Rights Reserved.

## Key features

- ISO 17025 certified frequency analysis
- 1-100 Hz spectrum coverage
- Live microphone input
- Video audio extraction
- Audio file analysis
- Forensic-grade sealed reports
- Single-tap activation

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Pro Analyst | $19.99 | per month |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro Analyst – Lifetime | $149.99 | one-time |
| Remove Ads | $2.99 | one-time |


## Is FreqCheck safe?

Not enough ratings yet to assess FreqCheck.

## Is FreqCheck legit?

FreqCheck: See Sound/Vibration has limited verification signals. The AppsHunter Legitimacy Score for FreqCheck is 58 out of 100 points across 7 verification signals from App Store and developer data.


## Frequently asked questions about FreqCheck

### What is FreqCheck?

FreqCheck is an ISO/IEC 17025:2017 certified frequency analyzer for iPhone and iPad. It measures sound frequencies in the 1 to 100 Hz spectrum, allowing users to see and analyze vibrations and tones.

### Does FreqCheck have ads?

Yes, FreqCheck contains advertisements. As a free application with in-app purchase options, advertisements are displayed to support its continued development and availability.

### What are the different modes in FreqCheck?

FreqCheck offers three input modes: LIVE for real-time microphone analysis, VIDEO to extract frequencies from video audio tracks, and AUDIO to audit the signal of any audio file.

### How does FreqCheck ensure the accuracy of its reports?

Reports are sealed with forensic layers including Device-Hash Anchoring, SHA-256 Sealing, and are digitally signed PDFs. This ensures the data is locked to the device and any alteration invalidates the report.

### What is the price of FreqCheck?

FreqCheck is available for free. There is an optional 'Pro Analyst' subscription available for $19.99 per month for users who require advanced features.

### What devices does FreqCheck support?

FreqCheck is designed for iPhone and iPad devices. It supports external microphones and DC coupled line-in for enhanced audio input.

### How often is FreqCheck updated?

The latest version, 1.1.1, was released on June 23, 2026. Updates are provided regularly to enhance functionality and reliability.

### What is the age rating for FreqCheck?

FreqCheck has an age rating of 4+. This indicates it is suitable for users of all ages, with no mature content restrictions.

## Version history (last 5 releases)

### 4.0.5 — 2026-10-23

What's New in Version 4.0.5

IEC Frequency Weighting & SLM Integration 
FreqCheck expands into a comprehensive, IEC 61672-compliant Sound Level Meter (SLM) for defense, occupational, and industrial testing.

Standard Acoustic Lenses: Toggle between Z-Flat (unweighted linear response from 0.2 Hz to 192 kHz), A-Weighted (OSHA/environmental noise), and C-Weighted (industrial peak compliance and low-frequency rumble) inside Pro Input Mode (PIM).

Time Integration & MIL-STD-1474E Safeguard: 
Apply standard Fast (125ms) or Slow (1000ms) RMS time-averaging for continuous noise monitoring. 

Critical MIL-STD-1474E Protocol: For ballistic shockwave and suppressor testing, always set Frequency Weighting to Z-Flat (Unweighted) and lock the clock to 192.0 kHz or 384.0 kHz to capture true microsecond Peak SPL (Lpk). Applying A-Weighting or relying on Fast/Slow RMS averaging during gunfire tests will artificially attenuate shockwave rise times and underreport blast overpressure.

Protected Metrology: 
To maintain Class 1 integrity, active Weighting and Time Integration selections are permanently stamped onto Layer 1 of every SHA-256 PDF Audit Report, ensuring complete transparency between raw ballistic captures and filtered metrics.

Full Post-Process Parity (Import Audio & Video Like Live Hardware) 
Every advanced capability inside Pro Input Mode (PIM)—including IEC Frequency Weighting (Z, A, C), Time Integration, WideBand 65k-point FFT resolution, and Dynamic Pulse Sequence (DPS) blast analysis—now executes with 100% mathematical parity on imported Audio (.wav, .flac, .alac, .aiff, .m4a, .mp3 up to 24-bit/384 kHz) and Video files. Configure your exact PIM sensor calibration, weighting, or MIL-STD-1474E parameters and audit pre-recorded range captures or dormant lab archives just like a live DAQ feed.

Raw 384.0 kHz Hardware Integration & 65k-Point FFT Unlocks 384.0 kHz sampling for 192.0 kHz WideBand acoustic auditing. Powered by a dynamic 65,536-point FFT architecture, the engine delivers enterprise spectral resolution at maximum clock speeds with live digital SPL readouts and Peak Hold captures.

Dynamic Pulse Sequence (DPS) & MIL-STD-1474E Blast Averaging 
Calculates true energetic logarithmic averages (Lavg) and instantaneous Peak SPL (Lpk) across multi-round strings per MIL-STD-1474E, ISO 10843, and ANSI S12.19. Configurable pulse counts (3–10), threshold gates (>130 dB), and anti-echo lockout windows (0.5–3.0s) aggregate into a unified report featuring max peak levels, energetic means, per-shot breakdowns, and a SHA-256 sequence hash.

Pro Input Mode (PIM) Bridging & Hardware DC Block 
PIM grants direct control over channel routing, ADC voltage ceilings, sensor sensitivity (mV/Pa or mV/g), and dual preset slots—bypassing iOS filters to bridge DC-coupled DAQs and instrumentation mics. A switchable Hardware DC Block eliminates electrical DC offsets while strictly preserving 0.2 Hz infrasound.

Forensic-Grade Cryptographic Proof 
Sessions conclude with an ISO/IEC 17025-calibrated, NIST-traceable PDF Audit Report secured by device-hash anchoring and real-time SHA-256 cryptographic sealing for evidentiary-weight documentation.

### 3.0.3 — 2026-10-08

What's New in Version 3.0.3 iPad Log Fix & UI Refinements

Resolves an issue preventing PDF log exports on iPad. Take full advantage of the larger canvas with a desktop-class Tactical Dashboard, giving your real-time FFT spectrum, multi-shot DPS sequences, and high-contrast SPL readouts the expansive visual real estate they deserve for true lab-bench analysis in the field.

Raw 384.0 kHz Hardware Integration & 65k-Point FFT

Building upon Tactical Wideband Metrology, FreqCheck now unlocks up to raw 384.0 kHz hardware sampling to support extreme 192.0 kHz high-frequency acoustic auditing. Powered by a new dynamic 65,536-point FFT architecture, the engine automatically scales up to deliver enterprise-grade spectral resolution at maximum hardware clock speeds. Complete with a massive digital meter displaying live Sound Pressure Level (SPL) and precise Peak Hold captures, this update transforms your iOS device into an industrial-grade spectrum analyzer with unprecedented metrology horsepower.

Dynamic Pulse Sequence (DPS) & MIL-STD-1474E Blast Averaging

Dynamic Pulse Sequence (DPS) introduces rigorous MIL-STD-1474E compliant metrology to calculate true energetic logarithmic averages across multi-round blast series and impulsive acoustic events. Because decibels are logarithmic representations of physical sound pressure, traditional arithmetic means severely underestimate the true physical energy delivered to human ears or blast gauges. DPS converts each discrete peak back into linear acoustic mean-square pressure, averages the physical energy, and computes the correct equivalent energy mean level (Lavg).

Configurable pulse counts (3 to 10 events), adjustable threshold sensitivity gates (e.g., >130 dB floor to filter out ambient range chatter or noise), and customizable anti-echo lockout windows (0.5s, 1.5s, or 3.0s to eliminate secondary ground and berm reflections) ensure flawless field automation.

Whether testing heavy ordnance, firearm suppressors, or industrial drop hammers, every multi-round session automatically aggregates into a unified sequence report featuring absolute peak levels (Lpk, max), energetic averages (Lavg), a detailed per-shot breakdown table, and a combined SHA-256 cryptographic sequence hash for tamper-evident proof.

Pro Input Mode (PIM) Bridging & Hardware DC Block

Integrated with Pro Input Mode (PIM), the system incorporates dedicated input channel selection (Left, Right, Auto), combined with manual overrides for ADC voltage ceilings, sensor sensitivity (mV/Pa), and dual hardware preset slots. This completely bypasses standard mobile audio filters and auto-gain compression, bridging your device directly to professional DC-coupled DAQ hardware and external instrumentation microphones.

Crucially, this update adds a switchable Hardware DC Block. This filter dynamically eliminates false electrical offsets from external hardware before the data hits the FFT—instantly zeroing inflated baseline SPL readings while strictly preserving the engine's 0.2 Hz infrasound metrology.

Your infrasound detector and acoustic toolkit scale seamlessly to your exact technical requirements, delivering pristine, unadulterated telemetry you can trust. Taking absolute control over your input variables guarantees your field readings match the accuracy of expensive lab bench equipment.

Forensic-Grade Cryptographic Proof

Every session concludes with an ISO 17025-calibrated, NIST-traceable PDF audit report secured by real-time SHA-256 cryptographic frame sealing. The architecture ensures that any attempt to alter the captured frequency analysis breaks the digital seal, guaranteeing the absolute integrity of your data.

You walk away with fully certified, evidentiary-weight documentation that commands immediate authority in any investigative, industrial, defense, or scientific setting. Presenting lab-grade, cryptographically sealed proof provides total confidence and professional peace of mind.

### 3.0.2 — 2026-09-21

What’s New in Version 3.0.2

**Raw 384.0 kHz Hardware Integration & 65k-Point FFT**
Building upon Tactical Wideband Metrology, FreqCheck now unlocks up to raw 384.0 kHz hardware sampling to support extreme 192.0 kHz high-frequency acoustic auditing. Powered by a new dynamic 65,536-point FFT architecture, the engine automatically scales up to deliver enterprise-grade spectral resolution at maximum hardware clock speeds. Complete with a massive digital meter displaying live Sound Pressure Level (SPL) and precise Peak Hold captures, this update transforms your iOS device into an industrial-grade spectrum analyzer with unprecedented metrology horsepower.

**iPadOS UI Refinements**
FreqCheck has been newly refined and optimized for the iPad. Take full advantage of the larger canvas with a desktop-class Tactical Dashboard, giving your real-time FFT spectrum, multi-shot DPS sequences, and high-contrast SPL readouts the expansive visual real estate they deserve for true lab-bench analysis in the field.

**Dynamic Pulse Sequence (DPS) & MIL-STD-1474E Blast Averaging**
Dynamic Pulse Sequence (DPS) introduces rigorous MIL-STD-1474E compliant metrology to calculate true energetic logarithmic averages across multi-round blast series and impulsive acoustic events. Because decibels are logarithmic representations of physical sound pressure, traditional arithmetic means severely underestimate the true physical energy delivered to human ears or blast gauges. DPS converts each discrete peak back into linear acoustic mean-square pressure, averages the physical energy, and computes the correct equivalent energy mean level (Lavg).

Configurable pulse counts (3 to 10 events), adjustable threshold sensitivity gates (e.g., >130 dB floor to filter out ambient range chatter or noise), and customizable anti-echo lockout windows (0.5s, 1.5s, or 3.0s to eliminate secondary ground and berm reflections) ensure flawless field automation.

Whether testing heavy ordnance, firearm suppressors, or industrial drop hammers, every multi-round session automatically aggregates into a unified sequence report featuring absolute peak levels (Lpk, max), energetic averages (Lavg), a detailed per-shot breakdown table, and a combined SHA-256 cryptographic sequence hash for tamper-evident proof.

**Pro Input Mode (PIM) Bridging & Hardware DC Block**
Integrated with Pro Input Mode (PIM), the system incorporates dedicated input channel selection (Left, Right, Auto), combined with manual overrides for ADC voltage ceilings, sensor sensitivity (mV/Pa), and dual hardware preset slots. This completely bypasses standard mobile audio filters and auto-gain compression, bridging your device directly to professional DC-coupled DAQ hardware and external instrumentation microphones.

Crucially, this update adds a switchable Hardware DC Block. This filter dynamically eliminates false electrical offsets from external hardware before the data hits the FFT—instantly zeroing inflated baseline SPL readings while strictly preserving the engine's 0.2 Hz infrasound metrology.

Your infrasound detector and acoustic toolkit scale seamlessly to your exact technical requirements, delivering pristine, unadulterated telemetry you can trust. Taking absolute control over your input variables guarantees your field readings match the accuracy of expensive lab bench equipment.

**Forensic-Grade Cryptographic Proof**
Every session concludes with an ISO 17025-calibrated, NIST-traceable PDF audit report secured by real-time SHA-256 cryptographic frame sealing. The architecture ensures that any attempt to alter the captured frequency analysis breaks the digital seal, guaranteeing the absolute integrity of your data.

You walk away with fully certified, evidentiary-weight documentation that commands immediate authority in any investigative, industrial, defense, or scientific setting. Presenting lab-grade, cryptographically sealed proof provides total confidence and professional peace of mind.

### 2.1.2 — 2026-09-14

What’s New in this Version

Version 2.1.2: Dynamic Pulse Sequence (DPS) & MIL-STD-1474E Blast Averaging

Dynamic Pulse Sequence (DPS) introduces rigorous MIL-STD-1474E compliant metrology to calculate true energetic logarithmic averages across multi-round blast series and impulsive acoustic events. Because decibels are logarithmic representations of physical sound pressure, traditional arithmetic means severely underestimate the true physical energy delivered to human ears or blast gauges. DPS converts each discrete peak back into linear acoustic mean-square pressure, averages the physical energy, and computes the correct equivalent energy mean level (Lavg).

Configurable pulse counts (3 to 10 events), adjustable threshold sensitivity gates (e.g., >130 dB floor to filter out ambient range chatter or noise), and customizable anti-echo lockout windows (0.5s, 1.5s, or 3.0s to eliminate secondary ground and berm reflections) ensure flawless field automation. 

Whether testing heavy ordnance, firearm suppressors, or industrial drop hammers, every multi-round session automatically aggregates into a unified sequence report featuring absolute peak levels (Lpk, max), energetic averages (Lavg), a detailed per-shot breakdown table, and a combined SHA-256 cryptographic sequence hash for tamper-evident proof.

Building upon Tactical Wideband Metrology, FreqCheck delivers 192 kHz sampling to support up to 96 kHz high-frequency acoustic auditing, complete with a massive digital meter displaying live Sound Pressure Level (SPL) and precise Peak Hold captures. 

This transforms your iOS device into an industrial-grade FFT spectrum analyzer capable of measuring extreme ballistic acoustic events and high-speed transients. You gain the unprecedented power to validate covert signals or high-frequency anomalies instantly in the field, turning raw data into undeniable proof. Having this caliber of WideBand metrology in your pocket ensures you are always prepared for the unexpected.

Integrated with Pro Input Mode (PIM), the system incorporates dedicated input channel selection (Left, Right, Auto), combined with manual overrides for ADC voltage ceilings, sensor sensitivity (mV/Pa), and dual hardware preset slots. This completely bypasses standard mobile audio filters and auto-gain compression, bridging your device directly to professional DC-coupled DAQ hardware and external instrumentation microphones. 

Your infrasound detector and acoustic toolkit scale seamlessly to your exact technical requirements, delivering pristine, unadulterated telemetry you can trust. Taking absolute control over your input variables guarantees your field readings match the accuracy of expensive lab bench equipment.

Every session concludes with an ISO 17025-calibrated, NIST-traceable PDF audit report secured by real-time SHA-256 cryptographic frame sealing. 

The architecture ensures that any attempt to alter the captured frequency analysis breaks the digital seal, guaranteeing the absolute integrity of your data. 

You walk away with fully certified, evidentiary-weight documentation that commands immediate authority in any investigative, industrial, defense, or scientific setting. 

Presenting lab-grade, cryptographically sealed proof provides total confidence and professional peace of mind.

### 2.1.1 — 2026-09-01

Version 2.1.1: Tactical Wideband Metrology

Tactical Wideband Metrology introduces 192 kHz sampling to support up to 96 kHz high-frequency acoustic auditing, complete with a massive digital meter displaying live Sound Pressure Level SPL and precise Peak Hold captures. 

This transforms your iOS device into an industrial-grade FFT spectrum analyzer capable of measuring extreme ballistic acoustic events and high-speed transients. 

You gain the unprecedented power to validate covert signals or high-frequency anomalies instantly in the field, turning raw data into undeniable proof. 

Having this caliber of WideBand metrology in your pocket ensures you are always prepared for the unexpected.

Building on the recently introduced Pro Input Mode (PIM), the system now incorporates dedicated input channel selection (Left, Right, Auto), combined with manual overrides for ADC voltage ceilings, sensor sensitivity (mV/Pa), and dual hardware preset slots. 

This completely bypasses standard mobile audio filters and auto-gain compression, bridging your device directly to professional DC-coupled DAQ hardware and external instrumentation microphones. 

Your infrasound detector and acoustic toolkit scale seamlessly to your exact technical requirements, delivering pristine, unadulterated telemetry you can trust. Taking absolute control over your input variables guarantees your field readings match the accuracy of expensive lab bench equipment.

Every session concludes with an ISO 17025-calibrated, NIST-traceable PDF audit report secured by real-time SHA-256 cryptographic frame sealing. 
The architecture ensures that any attempt to alter the captured frequency analysis breaks the digital seal, guaranteeing the absolute integrity of your data. 

You walk away with fully certified, evidentiary-weight documentation that commands immediate authority in any investigative, industrial, or scientific setting. 

Presenting lab-grade, cryptographically sealed proof provides total confidence and professional peace of mind.

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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 2026-10-24.*