Comparison

SPLnFFT Noise Meter vs HemiSync

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

SPLnFFT Noise Meter

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
Read full description

SPLnFFT is a sound level meter (noise meter) for your iPhone or iPad with many advanced features: frequency analyzer, frequency meter, test signal generator, dosimeter, ... This soundmeter App is the only one for iOS recommended by the "Laborers' Health and Safety Fund of North America". Here are extracts from other reviews: "our favorite sound measurement app" SafetyAwakenings.com "SPLnFFT is comprehensive, easy to use" TapeOp.com You will find more reviews here: https://www.facebook.com/SPLnFFT For daily use, a very simple interface displays the level of exposure: if orange or red, protect your ears ! Professional users will take advantage of a wide range of accurate and reliable measurements: Leq, peak, L10, L95, taktmaximal, frequency analysis, histogram, dosemetering, ... A&C weightings are compliant with ANSI® S1.42 standard. "468" refers to ITU-R 468-4 *** Some KEY INFORMATION *** : - you absolutely need to allow access to microphone to use this App - screen rotation must be un-locked - there are built-in help messages (speech bubble). Need more ? Contact us !: email, blog, Facebook,... - do not expect to measure as low as 0dB(A) in a quiet room, for these 2 reasons: 30-130dB(A) is the standard usable range for sound level meters and anyway a standard quiet room is around 30dB(A) whereas a typical anechoic chamber is 10 to 20dB(A) Top digital display is for measurement of sound power in 'slow' mode (averaged on 1s). Central analog display is for 'fast' mode (averaged on 1/8th s). But it can display 'slow' mode as well on request: just click on 'fast' label. Peak and average values are displayed below and are held until you touch the 'reset' label. The videos on Youtube reveal more details. Bottom view is a real time FFT (frequency analysis). You will notice that predominant frequency and next one are highlighted. Their frequencies and relative power are displayed on the right. If your input signal is a pure tone then this App will lock on its frequency and display a very accurate result. Green line is the result of a real time FFT done with 1024 points. Purple line is the averaged FFT (exponential filtering done on power of each frequency). Blue line is a copy of what the purple line was when the user froze the display the last time. A test tone at 1kHz or a white noise or a pink noise can be generated and sent to right and/or left outputs (select the type you want in BEEP tab). This FFT view - more precisely an upsized version of it - can be exported as a picture in your own photo library, using the camera button (when display is frozen only). This picture can be exported in a mail as well. The display can be flipped upside-down to ease reading: just rotate your iPhone while holding it vertically. As for ALL sound meters (thus including this one and all others at any price), calibration is suggested if you want to reach extreme precision. This is enabled in this App thanks to a slider to apply some compensation and to three non volatile memories (choice to be made in MIC. tab). How to ? For calibration, you need and external reference, either a calibrated sound meter, or a calibrated noise source. Note as well that the tiny embedded loudspeaker cannot reproduce extreme frequencies. Thus if you want to hear a real white or pink noise, you will need to use a quality headphone or HiFi system. This App was designed seriously for our own needs, by a signal processing expert, and is regularly updated to maintain accuracy and reliability. ***** Any comment, any feedback ? Click on 'support' in iTunes: there is a blog for this. You can even contact us directly by email or through the dedicated FaceBook page (note 'send email' top right) *****

About

HemiSync

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
Read full description

Explore Audio Frequency Meditation HemiSync is an audio frequency generator that creates binaural beats and isochronic tones for meditation and relaxation practice. The app allows you to experiment with different sound frequencies that some users find helpful for their personal wellness routines. What This App Does: Generates customizable audio tones and beats Offers preset frequency combinations based on popular meditation practices Provides session timers and audio controls Includes binaural beat and isochronic tone generation modes Features: Frequency range selection (Delta, Theta, Alpha, Beta, Gamma) Adjustable beat frequencies and carrier tones Pre-configured audio presets Session timer functionality Solfeggio frequency options (396Hz, 417Hz, 432Hz) Please Note: This app is for entertainment and personal exploration purposes. It generates audio tones based on concepts from audio meditation practices. Any effects experienced are subjective and individual. Privacy Policy - https://enginezero.tech/app-privacy-policy/ Terms of Use (EULA) - https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

SPLnFFT Noise Meter4 screens
HemiSync4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard6 real differences · 4 level
SPLnFFT Noise Meter versus HemiSync: the parameters behind the verdict, then further details
ParameterSPLnFFT Noise MeterHemiSync
Price$3.99Free — better
Rating4.8 (60 ratings) — better4.2 (9 ratings)
Positive reviews90.4% of reviews100.0% of reviews — better
Number of ratings60 — better9
Update frequencyEvery 2 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.2 — better18.4
Further details — not scored
Size4 MB61 MB
Age rating4+4+
DeveloperFabien LefebvreEngineZero

Customer experience

SPLnFFT Noise Meter

All ratings60 ratings
Positive95.0%
Neutral1.7%
Negative3.3%
Written reviews166 reviews
Positive90.4%
Neutral4.8%
Negative4.8%

HemiSync

All ratings9 ratings
Positive77.8%
Neutral22.2%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

SPLnFFT Noise Meter

Reported bugs

11 issues
  • 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
Show 6 more
  • Rotation setting notification appears on every app launch
  • iPhone 5s detected as iPhone 6 (potential calibration impact)
  • iPhone 6 support not included in updates
  • Readings drift to zero periodically on older iOS versions
  • Settings reset when app is closed (dB mode reverts)
  • Dead hyperlinks (OSHA reference)

Requested features

15 requests
  • 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
Show 10 more
  • Waterfall diagram with spectrum replay capability
  • SIL scales (e.g., SIL4) support
  • Silent alarm for loud environments
  • Video recording with dB level overlay
  • Ability to save and replay FFT spectral data over time
  • Better app icon design
  • Tutorial or help documentation for acoustic terminology
  • Default email address field for result sharing
  • Bluetooth audio input support
  • Bar graph scale and cursor labeling improvements

HemiSync

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

SPLnFFT Noise Meter

One-time1
  • Export raw data to Dropbox + PRO features$4.99
1 purchases

HemiSync

Subscriptions1
  • Premium$0.991 Month

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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