# Seeing Sound

Source: https://www.youtube.com/watch?v=dJtzXpW15HI
Recap page: https://rapidrecap.app/video/dJtzXpW15HI
Generated: 2025-11-14T17:45:53.897+00:00

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## Quick Overview

The video demonstrates the capability of the Fluke ii915 Acoustic Imager to locate subtle, high-frequency sounds, successfully identifying a tire puncture leak and pinpointing ultrasonic noise sources from electronic components like a power supply transformer and a Marx generator, even in noisy environments, by visualizing sound intensity across a frequency spectrum.

**Key Points:**
- The Fluke ii915 Acoustic Imager successfully located a slow air leak in a white Toyota Matrix tire by visualizing bubbling soap water around the puncture point (0:05-0:24).
- The device detected high-frequency noise (ultrasonic) escaping a leaking gas pipe connection on a structure clad in OSB, proving its use for detecting leaks invisible to the naked ear (4:08-4:38).
- The presenter used the imager to locate a buzzing noise originating from a switching power supply transformer, which was vibrating at frequencies between 15 kHz and 35 kHz (6:55-7:44).
- A custom-built 'S' shape array of 22 ultrasonic transmitters (resonating at 40 kHz) was used to test the imager's spatial resolution, clearly mapping the sound sources (11:02-11:36).
- The imager detected corona discharge noise (up to 70 kHz) from a high-voltage Marx generator, demonstrating its application in locating electrical discharge sources that cause audible noise (8:45-9:33).
- The device displays an overlay of sound intensity (color-coded from blue/low to red/high) onto a visible light image, alongside a real-time spectral analysis graph (3:37, 3:40).

![Screenshot at 0:26: The presenter holds the Fluke ii915 Acoustic Imager while pointing at the tire of a white car, demonstrating its ability to visually locate the source of the air leak via ultrasonic imaging overlaid on the live video feed.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-00-26.png)

**Context:** The video serves as a practical demonstration showcasing the versatility and effectiveness of the Fluke ii915 Acoustic Imager, a specialized tool designed to visualize sound, particularly in the ultrasonic range (2 kHz to 100 kHz). The presenter, Mehdi Sadaghdar, conducts several tests—locating a tire leak, finding a gas leak, diagnosing high-frequency noise in electronics, and visualizing standing waves from an ultrasonic array—to prove the device's value for predictive maintenance and failure analysis in various industrial and technical settings.

## Detailed Analysis

The presenter begins by using the Fluke ii915 Acoustic Imager to find a slow leak in a tire, applying soapy water and confirming the escaping air with the imager's ultrasonic visualization (0:05-0:24). Next, the demonstration moves outdoors where the imager successfully detects a faint gas leak from a rusty pipe connection near a gas meter, highlighting its safety application in finding leaks that are otherwise inaudible or difficult to locate (4:08-4:38). Inside, the presenter uses the device to diagnose high-frequency noise (coil whine) from an open switching power supply, pinpointing the vibrating transformer around 15-35 kHz (6:55-7:44). To demonstrate spatial resolution, the presenter uses a custom cardboard array featuring 22 ultrasonic transmitters wired to an Arduino, which generate visible sound patterns (especially at 40 kHz) when powered, allowing the imager to map the individual sound sources clearly (11:02-11:36). Finally, the device is used to visualize corona discharge noise from a Marx generator, showing intense ultrasonic activity (up to 70 kHz) emanating from the high-voltage components, proving the imager's utility in complex electrical environments (8:45-9:33). The presenter emphasizes that the device's 64 microphones and phase difference calculations allow it to accurately map sound sources, even in extremely noisy environments, making it superior to traditional methods for locating leaks and vibrations.

### Tire Leak Detection

- Soap water application on a flat tire
- ii915 visualizes leak noise around 20-30 kHz
- Confirms leak location precisely (0:05-0:24)

### Gas Leak Detection

- Scanning rusty gas meter piping outdoors
- Imager detects ultrasonic noise indicating a leak at the connection points (4:08-4:38)

### Electronics Noise Analysis

- Diagnosing a switching power supply
- Identifies vibration from a transformer primarily between 15 kHz and 35 kHz (6:55-7:44)

### Acoustic Array Test

- Testing resolution with a custom '8' shape array of 22 ultrasonic transmitters
- Shows clear, distinct sound spots corresponding to each transmitter (11:02-11:36)

### High Voltage Test

- Visualizing corona discharge from a Marx generator
- Pinpoints high-frequency noise sources up to 70 kHz on the high-voltage equipment (8:45-9:33)

### Product Features

- Device uses 64 microphones and phase differences to map sound intensity
- Spectral analysis bar shows frequency distribution of detected sound (4:57, 10:02)

![Screenshot at 0:15: The Fluke ii915 Acoustic Imager sprays soapy water on a tire to reveal an air leak via ultrasonic visualization.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-00-15.png)
![Screenshot at 0:37: The acoustic image overlay clearly highlights the ultrasonic leak noise escaping the tire tread with a bright red/yellow spot \(approx. 30-60 kHz range\).](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-00-37.png)
![Screenshot at 2:21: Demonstration of the imager detecting ultrasonic noise \(peaks above 40 kHz\) from a small gas leak on a portable stove burner.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-02-21.png)
![Screenshot at 3:30: The imager detects ultrasonic noise leaks from pressurized pipes in a construction setting, showing distinct hotspots on the tubing.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-03-30.png)
![Screenshot at 4:27: Close-up view of the gas meter using the imager, showing faint ultrasonic leakage detected at the pipe fittings.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-04-27.png)
![Screenshot at 5:54: The acoustic map overlays the circuit board of a power supply, clearly showing a strong noise source \(red/yellow\) localized around a component \(transformer/inductor\).](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-05-54.png)
![Screenshot at 8:57: The presenter uses the imager to detect ultrasonic noise generated by corona discharge on a large metallic sphere \(Van de Graaff generator component\).](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-08-57.png)
![Screenshot at 10:00: The workbench setup showing multiple multimeters and a Keysight oscilloscope running while the presenter tests the ultrasonic transmitter array.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-10-00.png)
![Screenshot at 11:38: The sound map generated by the ultrasonic array shows clear, distinct hot spots corresponding to the location of each transmitter, confirming spatial accuracy.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-11-38.png)
![Screenshot at 12:53: The presenter smiles while showing the complex acoustic map generated by the ultrasonic array, demonstrating the device's ability to resolve many sound sources simultaneously.](https://ss.rapidrecap.app/screens/dJtzXpW15HI/00-12-53.png)