EyeSound Vocal vs Sound Level & Spectrogram
Price, ratings, monetisation and update history for both apps, side by side โ with what reviewers say about each.
EyeSound Vocal
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EyeSound Vocal converts spoken words and other sounds into data rich images. These are seen in an active spectrogram displayed on the screen of your device. Latency of sound-to-image is less than 100 milliseconds. The spectrogram can be tuned by the user so that images of most spoken words are recognizable and are unique. If one has memorized a good sized vocabulary of word images, there can be some visual comprehension of spoken conversations just from viewing the app's spectrogram. Details in the spectrograms indicate inflection and volume. Applications/uses: - entertainment - watch as sounds and conversations morph into image streams - art - create and download spectrogram images that correspond to spoken phrases or other sounds ------------------------------------------------ NOTE: EyeSound Vocal does not capture medical data and does not provide health related measurements, diagnoses or treatment advice. It is not intended for use as a tool for treatment of medical conditions. It is not intended for use as a tool for scientific measurements. ------------------------------------------------ User adjustable parameters in the app include the rate at which sonogram images progress across the screen, resolution, colors, color switching and color mapping to sound intensity, high frequency boost. Features include auto gain, display of saved images next to active or paused spectrogram, pause/resume for capture of images, save/recall of images, save/recall of setup parameters, default parameter setup that is well suited to the visualization of human speech. full screen mode for a view of nothing but the active, or paused, spectrogram. How the app works: Sound is captured by your device's microphone. The app processes the sound data in small sized packets. For each packet the app computes frequencies and intensities. A spectrogram is created by color mapping intensities across frequency bins and then plotting these versus time. With ongoing plotting of packet data as it arrives the spectrogram becomes 'active' - it appears as a movie. EyeSound - Past, Present, Future: 45 years ago, in 1979, a young chemical engineer fresh out of MIT had just begun working for GE in Niskayuna, NY. In his spare time he built and experimented with breadboarded circuits that incorporated resistors and capacitors, transistors and ICs and lights, microphones and speakers. One day he assembled a device consisting of a row of LEDs tied into a circuit that would sequentially light the LEDs in accordance with an input voltage signal. When he manually swept this device in an arc he saw - very much to his surprise and to his fascination - images of complex waveforms painted across empty air. This simple device was giving a glimpse of all of the information that was normally only heard! The engineer had found a mission: improve upon the device to open to the world a whole new dimension of visual perception. A team of 2 of us - the engineer and the coder - have over the past several months turned the concept into an app. The initial release is happening now. The 45 year old mission is on the verge of realization. We anticipate releasing new versions of the EyeSound Vocal app on a regular basis. Users - please send us your suggestions and we'll use them as direction for improvements and use them to expand on our user tips. We will be taking a look into interfacing EyeSound with two types of peripheral devices (1) AR glasses which could put the active spectrogram front and center in your field of view - so that while viewing the spectrogram you will be more in the same world with the people around you; (2) wearable, directional and better quality microphones to avoid the pick up of background sounds that at times obscure the visualizations.
Sound Level & Spectrogram
Measure sound levels in decibels and visualize sound frequencies with a real-time spectrogram. Understand your environment's noise and protect your health. Offers advanced settings for accurate acoustic analysis.
- 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
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"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.
Screenshots
Verdict
The clearest difference is ads: EyeSound Vocal at none against Sound Level & Spectrogram's shown. EyeSound Vocal also leads on update cadence (every 3 weeks vs every 5 months). On price, in-app purchases, device support and iOS requirement there is nothing between them.
Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
EyeSound Vocal ships an update every 3 weeks, Sound Level & Spectrogram every 5 months. The most recent releases landed on September 12, 2026 and September 18, 2026 respectively.
| Parameter | EyeSound Vocal | Sound Level & Spectrogram |
|---|---|---|
| Price | Free | Free |
| Positive reviews | โ | 100.0% of reviews |
| Update frequency | Every 3 weeks โ better | Every 5 months |
| Ads | No โ better | Yes |
| In-app purchases | No | No |
| Monetization | โ | Ad-supported |
| Devices | iPhone, iPad โ better | iPhone |
| Requires iOS | 17.0 โ better | 18.7 |
| Further details โ not scored | ||
| Size | 3 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | keith house | TOON,LLC |
In-app purchases
EyeSound Vocal
No in-app purchases
Sound Level & Spectrogram
No in-app purchases
Questions
Is EyeSound Vocal free?
Is Sound Level & Spectrogram free?
Do EyeSound Vocal or Sound Level & Spectrogram have ads?
Which is updated more often, EyeSound Vocal or Sound Level & Spectrogram?
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