SPL Graph vs Ultrasonic Analyzer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SPL Graph
This app analyzes sound pressure levels and environmental noise in real-time. It logs audio, captures video, and performs frequency analysis, with options for advanced octave band analysis and professional microphone integration. Receive email notifications for exceeding noise limits and auto-save data for continuous monitoring.
- Real-time sound pressure level analysis
- Audio recording and playback
- Optional video capture
- Octave and 1/3 octave band analysis
- 3D frequency plot
- Ln SPL value calculation
- Email notifications for noise limits
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SPL Graph is an audio Sound Pressure Level (SPL) environmental noise analyzer, real-time frequency analyzer, chart recorder and data logger. It includes: * Plot sound level over time * Record audio while plot is running, playback to identify sounds that may have caused problems * Capture video of events (optional in-app purchase) * Do octave and 1/3 octave band analysis (optional in-app purchase) * Show a 3D Plot of octave or 1/3 octave results * Calculate Ln SPL values, L01, L10, L50, L90, L95, LMax and LMin * Email notifications when sound exceeds pre-set limits * Auto-save results after set intervals, and email the results to you * Start another plot after auto-saving for continuous operation SPL Graph works by averaging the SPL for a period of time that can vary from 0.1 second to 60 minutes, applying an optional weighting filter, and plotting the sound level, recording the raw audio signal, if recording is turned on. For sound intervals of 1.0 second to 60 minutes, the optional octave and 1/3 octave logging modules allows storing the spectrum of the sound, for each interval. The app works very well with the built-in iOS device microphone. To upgrade the app to true professional standards, add our iTestMic, iPrecisionMic, or iAudioInterface2 with an appropriate microphone, and get ANSI or ISO Type 1 or 2 results. With iPrecisionMic, you can send the system in to our calibration lab and get a calibration certificate for ISO 61672 and ANSI S1.4. SPL Graph can record up to 24 hours of sound level data, with single second resolution. The graph starts with a one-minute plot window, and as a minute is recorded, the graph re-scales automatically and adds another minute to show the data collected so far. The overall SPL level, or LEQ, is displayed for whatever portion of the test is showing on the graph. Tap the play button to play back the recorded audio, and you can use the cursor to scrub the audio location on the graph. Use this feature to listen to events that you can see on the graph. With the optional octave logging module, you can also record the octave or 1/3 octave band levels. And, you can view the data on the 3D plot for a graphical view of frequency over time. You can scroll and scale the graph vertically, in dB, by using standard swipe and pinch gestures. You can also scroll and expand and contract the time axis using gestures. Zoom out to a full 24 hours, or zoom in to a single minute, showing second resolution. Double-tap the screen to zoom out to show the entire graph on the screen. The time scale grid changes dynamically, highlighting minutes, ten-minute, and hour lines as as it runs. As the graph runs, the overall LEQ (average SPL) for the entire time period is computed and displayed on the screen. Swiping across the graph brings up a cursor that displays the exact dB level and time for any point on the graph. You can turn on audio recording, so that you have a record of the sounds that were happening while the graph was being stored. You can use this to figure out exactly what the sound was that caused a peak on the graph, for example. Recordings can be compressed or uncompressed. If you exit the app, or are interrupted with a phone call, the graph data will not be lost. SPL Graph will automatically save the graph, and reload it when you next open the program. You can also save a graph in one of ten files on the iPhone, so that you can recall the graph later. SPL Graph supports saving graphs directly on your iOS device. You can recall these graphs and bring them up on the screen, and listen to the sounds that were made while the graph was recorded. You can also store an image of the screen to your photo roll. Use Dropbox or iTunes Files Sharing to export the results to your computer. You can also export data in tab-delimited files for XLS import using iCloud. The filters are all ANSI type 1 or better, and include A-weighting, C-weighting, and all octaves band filters from 32 to 16kHz.
Ultrasonic Analyzer
This app provides real-time audio analysis with visual representations of sound frequencies. It allows users to listen to and analyze ultrasounds, with options for transposed playback and slowed-down analysis of inaudible sounds. It supports various sampling rates and offers detailed charting and measurement tools.
- Real-time spectrum analysis
- Spectrogram and oscilloscope views
- Octave RTA analyzer
- Transposed ultrasound listening
- Slowed-down playback
- High sampling rates up to 384kHz
- Zoom and pan capabilities
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Ultrasonic Analyzer is a real-time spectrum, spectrogram, oscilloscope, and octave RTA analyzer for your iPhone or iPad. It provides a visual representation of ultrasounds using a sampling rate of up to 384kHz**. You can listen to transposed ultrasounds* and analyze them in real time. For sounds that are normally inaudible, a slowed-down playback option is also available. Ultrasonic Analyzer can be used to analyze the calls of various animals (e.g., bats, dolphins), measure the frequency response of high-end audio equipment, or evaluate ultrasonic sensors. Additionally, it allows you to analyze short imported audio files within a spectrogram context. Features - Sampling rates: 44.1kHz, 48kHz, 96kHz, 192kHz, 200kHz, 250kHz, 384kHz** - Real-time transposed ultrasound listening during recording* - Spectrogram analyzer: Color and black & white modes - Spectrum analyzer - Oscilloscope (full FFT window size) - Octave RTA analyzer: Bands – full, 1/3, 1/6, 1/12 (RMS values) - Max/min Octave RTA values - dBFS Meter - Fast real-time response - Adjustable spectrogram frequency resolution - Configurable time interval between FFT computations, with values as low as 1ms or even lower - Fast Fourier Transform (FFT) - FFT window sizes: 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536 - Recording trigger: Automatically triggers based on specified frequency bands - Zoom and pan capabilities for all charts - Measurement tools available in all charts - Playback analysis - Transposition during playback - Slow-down playback: Transpose octaves down for easier analysis - Picture-in-Picture (PIP) mode: Allows simultaneous spectrogram analysis with a secondary chart (Octave RTA, Spectrum, or Oscilloscope) - Audio input support: Built-in microphone, external microphone (via USB camera adapter or iPhone/iPad dock connector – Core Audio compliant devices) - Sharing options: Share charts and audio recordings via email, social networks, or clipboard - Exporting capabilities: Save audio recordings (WAV) and image charts (PNG) to iOS Document Browser - Audio file import: Load short audio files from other apps or the iOS Document Browser - Supported audio formats: WAV, CAF, AAC, MP3 - Automatic sample rate conversion for imported files - Frequency scale options: Linear and logarithmic - Amplitude scale options: Linear and logarithmic (dBFS) - dBFS Meter weighting: dBZ (linear) - Adjustable spectrogram length (dependent on resolution settings) Tested with (via USB adapter): - Dodotronic Ultramic200K, Ultramic250K, Ultramic384K - Pettersson M500-384 - Avisoft UltraSoundGate 116Un Make sure you are using the latest iOS update. *Requires an external microphone with ultrasonic capabilities connected via a USB adapter. **Real-time analysis at a 96kHz sample rate or higher is only possible with an external USB microphone. Alternatively, you can import files recorded on an external device for non-real-time analysis.
Screenshots
Verdict
The clearest difference is price: SPL Graph at $9.99 against Ultrasonic Analyzer's $19.99. SPL Graph also leads on review sentiment (64% vs 56%). Ultrasonic Analyzer's advantage is in-app purchases (none vs 5) and rating (3.9 vs 3.7). On update cadence, ads, monetization model and device support 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
SPL Graph costs $9.99 and Ultrasonic Analyzer $19.99 up front. SPL Graph sells 5 in-app purchases, starting at $19.99 per month. Ultrasonic Analyzer asks for nothing beyond the download.
Ultrasonic Analyzer holds the better App Store score, 3.9 against 3.7. That said, the two scores are not equally well evidenced: Ultrasonic Analyzer has 35 ratings behind it against 3, so its average is the more settled of the two. Written reviews complicate that: 64% of SPL Graph's written reviews are positive against 56% of Ultrasonic Analyzer's, so the app with the better star average is not the one people write more warmly about.
SPL Graph ships an update every 6 months, Ultrasonic Analyzer every 4 months. Both last shipped on October 23, 2026.
| Parameter | SPL Graph | Ultrasonic Analyzer |
|---|---|---|
| Price | $9.99 — better | $19.99 |
| Rating | 3.7 (3 ratings) | 3.9 (35 ratings) — better |
| Positive reviews | 64.3% of reviews — better | 55.9% of reviews |
| Number of ratings | 3 | 35 — better |
| Update frequency | Every 6 months | Every 4 months — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 12.4 — better |
| Further details — not scored | ||
| Size | 30 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Andrew Smith | DEXUS Pawel Krzywdzinski |
Customer experience
SPL Graph
Ultrasonic Analyzer
In-app purchases
SPL Graph
- Remote Noise Monitoring7 Days trial$19.991 Month
- Remote Noise Mid Level7 Days trial$79.991 Month
- Remote Noise Large7 Days trial$149.991 Month
- Octave Band SPL Logging$9.99
- Video Capture Option$19.99
Ultrasonic Analyzer
No in-app purchases
Questions
Is SPL Graph free?
Is Ultrasonic Analyzer free?
Which has better reviews, SPL Graph or Ultrasonic Analyzer?
Do SPL Graph or Ultrasonic Analyzer have ads?
Which is updated more often, SPL Graph or Ultrasonic Analyzer?
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