Acoustic cameras turn invisible sound into visible images. This guide explains how they work, where they're used, and how to choose the right one for your application. What Is an Acoustic Camera? An acoustic camera is a device that locates and visualizes sound sources in real time. It combines a microphone array — typically 64 to 200+ MEMS microphones arranged in a specific pattern — with a video camera and signal processing software. The result is a color-coded overlay on a live video feed, showing exactly where sound is coming from and how loud it is. Think of it as a thermal camera, but for sound instead of heat. Where a thermal camera shows hot spots in red, an acoustic camera shows loud spots — pinpointing the exact location of a leak, a faulty bearing, or an electrical discharge that you can't see with your eyes. The technology was originally developed for aerospace and automotive NVH (Noise, Vibration, and Harshness) testing. Today, it has expanded into industrial maintenance, energy utilities, manufacturing quality control, and building acoustics. How Does an Acoustic Camera Work? How an acoustic camera uses beamforming: sound waves arrive at each microphone with different time delays (Δt), the processor combines all signals, and outputs a color-coded sound map. The Microphone Array At the core of every acoustic camera is a microphone array — a precisely arranged set of MEMS (Micro-Electro-Mechanical Systems) microphones. The number of microphones directly affects performance: 64 microphones: Entry-level, suitable for general-purpose sound source localization 128 microphones: Professional-grade, better resolution and dynamic range 200+ microphones: High-end, capable of detecting subtle sources in noisy environments The spatial arrangement of these microphones matters as much as the count. Common configurations include circular, spiral (Fibonacci), and grid patterns. Each has trade-offs: spiral arrays offer good broadband performance, while grid arrays are better for near-field measurements. Beamforming: The Core Algorithm The key technology behind acoustic cameras is beamforming — a signal processing technique that combines signals from multiple microphones to "focus" on specific locations in space. Here's a simplified explanation: A sound wave arrives at each microphone at slightly different times (because each microphone is at a different distance from the source) The software calculates the expected time delay for every possible source location in the field of view For each candidate location, it shifts and sums the microphone signals according to the calculated delays Locations where the shifted signals add up constructively are identified as sound sources This process is repeated for every pixel in the image, producing a "sound map" that shows the spatial distribution of sound energy. Beamforming vs. Acoustic Holography There are two main acoustic imaging technologies: FeatureBeamformingAcoustic Holography (NAH)Best frequency rangeMid to high frequencies (>500 Hz)Low frequencies (<2 kHz)Measurement distanceFar-field (>1 meter)Near-field (<30 cm from source)ResolutionLimited by wavelength and array sizeHigher resolution at low frequenciesSpeedReal-time capableRequires careful scanningBest forLeak detection, general noise mappingEngine NVH, vibration analysis Most modern acoustic cameras use beamforming as the primary method because it works in real time and doesn't require the camera to be positioned close to the source. Some advanced systems support both technologies for maximum flexibility. The Role of the Video Camera The microphone array generates a sound map; the video camera provides the visual reference. The software overlays the sound map onto the video feed as a color-coded heat map, allowing the user to instantly see which component, pipe, or connection is producing the sound. High-end systems use depth cameras (such as Intel RealSense) to create 3D acoustic maps, enabling more accurate source localization on complex geometry. Frequency Range: Why It Matters Different applications require different frequency ranges: ApplicationTypical Frequency RangeWhyCompressed air leak detection20–50 kHzLeaks produce high-frequency hissingPartial discharge detection20–100 kHzElectrical discharges emit ultrasonic signalsMechanical fault detection1–20 kHzBearing wear, misalignment produce audible noiseAutomotive NVH100 Hz–10 kHzRoad noise, wind noise, engine noiseBuilding acoustics50 Hz–8 kHzLow-frequency structure-borne noise An acoustic camera with a frequency range of up to 100 kHz can handle virtually all industrial applications, including ultrasonic leak and partial discharge detection. Cameras limited to 20 kHz are suitable only for audible noise analysis. Key Applications Acoustic camera detecting vacuum leaks in composite materials — the color overlay pinpoints the exact leak location on the surface. Partial discharge detection on high-voltage insulators — the acoustic camera identifies discharge locations from a safe distance, combined with infrared thermal imaging for comprehensive diagnostics. 1. Compressed Air Leak Detection Compressed air is one of the most expensive energy sources in a factory. Studies show that 20–30% of compressed air is lost to leaks. An acoustic camera can scan an entire production line in minutes, identifying leaks that are invisible and inaudible to human ears. Why acoustic cameras beat traditional methods: Ultrasonic leak detectors require you to check one point at a time; an acoustic camera scans an entire area at once Visual overlay pinpoints the exact location — no guessing Many systems can estimate leak rate and annual cost, helping you prioritize repairs 2. Electrical Partial Discharge Detection Partial discharge (PD) is an early warning sign of insulation failure in high-voltage equipment — transformers, switchgear, cables, and bus bars. Left undetected, PD leads to complete insulation breakdown and potentially catastrophic failure. Acoustic cameras detect PD by capturing the ultrasonic emissions (typically 20–100 kHz) that accompany electrical discharge. The advantage over traditional PD detection methods: Non-contact: No need to de-energize equipment Real-time visualization: See exactly where the discharge is occurring Safe distance: Inspect live equipment from several meters away 3. Mechanical Fault Diagnosis Worn bearings, misaligned shafts, loose components, and valve leaks all produce characteristic sound signatures. An acoustic camera can identify and locate these faults before they lead to unplanned downtime. Common use cases: Motor and pump bearing wear detection Steam trap malfunction Valve leak identification Gearbox noise analysis 4. Automotive and Aerospace NVH Testing This is where acoustic cameras originated. NVH engineers use them to: Identify wind noise sources on vehicle bodies Locate rattles and squeaks in interior trim Analyze tire/road noise contributions Map engine noise radiation patterns Validate sound package effectiveness For NVH applications, large-aperture arrays (200+ microphones) provide the resolution needed to distinguish closely spaced sources. 5. Noise Compliance and Building Acoustics Environmental noise regulations require manufacturers to identify and reduce noise emissions. Acoustic cameras help: Map factory noise sources for compliance reporting Identify noise paths in buildings (walls, windows, HVAC) Verify effectiveness of noise barriers and enclosures 6. UAV-Mounted Acoustic Inspection A newer application: mounting acoustic cameras on drones for inspection of hard-to-reach infrastructure. Applications include: Power line and substation inspection Wind turbine blade inspection Pipeline corridor leak surveys Tall structure noise mapping Types of Acoustic Cameras Four form factors of acoustic cameras: Handheld (CRY8124), Fixed-Mount (CRY2623M), Large Array (CRY8500 SonoCAM Pi), and UAV-Mounted (CRY2626G). Handheld Acoustic Cameras Portable, battery-powered devices for field use. Typically 64–128 microphones with a built-in display. Best for maintenance rounds, leak detection, and quick inspections. Pros: Portable, easy to use, quick deployment Cons: Limited microphone count, smaller array = lower resolution at distance Fixed/Mounted Acoustic Cameras Permanently installed for continuous monitoring. Used in power substations, data centers, and critical infrastructure. Can run 24/7 with automated alerts. Pros: Continuous monitoring, automated alerting, no operator needed Cons: Fixed field of view, higher installation cost Large-Array Systems 200+ microphones on a larger frame. Used for NVH testing, pass-by noise measurement, and research applications. Often mounted on tripods or overhead structures. Pros: Highest resolution, widest frequency range, best for complex analysis Cons: Not portable, requires setup, higher cost UAV-Mounted Systems Lightweight acoustic arrays designed for drone mounting. Used for remote inspection of power lines, pipelines, and industrial facilities. Pros: Access to hard-to-reach locations, large-area surveys Cons: Flight time limits, vibration interference, regulatory requirements How to Choose the Right Acoustic Camera Quick decision guide: Choose your acoustic camera based on primary application. Step 1: Define Your Primary Application Your application determines the minimum specifications: ApplicationMin. MicrophonesFrequency RangeForm FactorCompressed air leak detection64Up to 50 kHzHandheldPartial discharge detection64–128Up to 100 kHzHandheld or fixedMechanical fault diagnosis64Up to 20 kHzHandheldNVH testing128–200+100 Hz–20 kHzLarge arrayContinuous monitoring64–128Application-dependentFixedDrone inspection64–128Up to 50 kHzUAV-mounted Step 2: Consider the Environment Noisy factory floor? You need more microphones and advanced algorithms to separate the target signal from background noise Outdoor use? Look for weather-resistant designs and wind noise rejection Hazardous area? Check for ATEX/IECEx certification Large distance? More microphones = better resolution at range Step 3: Evaluate the Software The hardware captures the data; the software turns it into actionable information. Key software features to look for: Real-time display: See the sound map live as you scan Frequency filtering: Isolate specific frequency bands to focus on particular issues Leak rate estimation: Quantify the cost of leaks in dollars or energy units Reporting: Generate professional reports with screenshots, measurements, and recommendations AI-assisted detection: Automatic identification of leak patterns and fault signatures Step 4: Compare Specifications Key specs to compare across manufacturers: SpecificationWhat It MeansWhat to Look ForMicrophone countMore mics = better resolution and sensitivity64 minimum; 128+ for demanding applicationsFrequency rangeDetermines what you can detectUp to 100 kHz for PD and ultrasonic leaksDynamic rangeAbility to measure both quiet and loud sources>70 dB for industrial environmentsAngular resolutionAbility to separate nearby sourcesSmaller is better; depends on frequency and distanceFrame rateHow quickly the sound map updates>10 fps for real-time scanningWeight and sizePortability<2 kg for handheld daily-use devicesBattery lifeRuntime for field use>3 hours for a full shift of inspectionsIP ratingDust and water resistanceIP54 or higher for industrial environments CRYSOUND Acoustic Camera Solutions CRYSOUND offers one of the widest product lines in the acoustic camera market — covering handheld, fixed-mount, large-array, and UAV-mounted form factors from a single manufacturer. Product Lineup CRY2624: 128-microphone handheld acoustic camera with ATEX certification — portable, field-ready, and safe for hazardous environments CRY8124: 200 MEMS microphones, frequency range up to 100 kHz — handles both audible noise analysis and ultrasonic applications (leak detection + partial discharge) in a single device CRY2623M: Fixed-mount version for 24/7 continuous monitoring of substations and critical infrastructure CRY8500 Series (SonoCAM Pi): Large spiral microphone array for NVH testing, pass-by noise measurement, and advanced acoustic research CRY2626G: Drone-mounted acoustic camera for remote inspection of power lines, pipelines, and wind turbines CRYSOUND acoustic camera product family: from handheld to drone-mounted solutions. Key Differentiator 1: Modular Sensor Expansion Unlike most competitors that offer a fixed-function device, CRYSOUND's acoustic cameras support external sensor modules for expanded capabilities: Infrared thermal imaging module: Combines acoustic and thermal data in a single view — when inspecting power equipment, engineers can simultaneously see the acoustic signature of partial discharge and the thermal hot spot of overheating components. This dual-mode inspection is widely used in power utilities for comprehensive substation diagnostics. IA3104 Contact Ultrasound Sensor: An external contact-type ultrasonic probe designed specifically for valve internal leak detection. The sensor couples directly to the metal surface of a valve, capturing high-frequency ultrasonic signals generated by internal leakage. Combined with intelligent analytics and guided workflows, it automates the full diagnostic process — from data acquisition to leak classification. This is critical for preventive maintenance of oil pipeline valves and natural gas network valves. This modular approach means a single CRYSOUND acoustic camera can serve as a comprehensive inspection platform, rather than requiring separate instruments for each detection task. Key Differentiator 2: Acoustic Link Mobile App CRYSOUND's Acoustic Link is a companion mobile app that connects to the acoustic camera via Wi-Fi. It enables: On-device preview: View captured photos, videos, and inspection reports on your phone or tablet — no PC required Defect-specific visualization: Retrieve gas-leak acoustic maps, partial-discharge patterns, and thermal images directly in the app One-tap sharing: Save results locally and share via the system share sheet for instant communication with colleagues and customers Automated report generation: Generate and export professional inspection reports from the field, eliminating the need to return to the office for post-processing For field inspection teams, this means faster turnaround from detection to documentation. Key Differentiator 3: Complete Acoustic Ecosystem Beyond acoustic cameras, CRYSOUND manufactures electroacoustic test systems (CRY6151B), acoustic test chambers, and calibration equipment — enabling complete acoustic testing solutions from a single vendor. With 28 years of experience and over 10,000 customers across 90+ countries, CRYSOUND brings deep domain expertise to every product. Explore CRYSOUND Acoustic Camera Products → Frequently Asked Questions What is the difference between an acoustic camera and a sound level meter? A sound level meter measures the overall sound pressure level at a single point. It tells you how loud it is, but not where the sound comes from. An acoustic camera shows both the location and the intensity of sound sources, making it far more useful for diagnosing and fixing noise problems. How far away can an acoustic camera detect a leak? Detection range depends on the leak size, background noise, microphone count, and frequency range. A typical handheld acoustic camera with 64–128 microphones can detect a 1mm compressed air leak from 10–30 meters away. Larger leaks can be detected from even greater distances. Can an acoustic camera work in a noisy factory? Yes. Modern acoustic cameras use beamforming algorithms that can isolate specific sound sources even in high-background-noise environments. The key is having enough microphones — more microphones provide better noise rejection and higher signal-to-noise ratio. Do I need training to use an acoustic camera? Basic operation is straightforward — point the camera, look at the screen, and identify the highlighted areas. Most users can start finding leaks within minutes. However, interpreting complex acoustic patterns (NVH analysis, partial discharge classification) benefits from training and experience. What is the ROI of an acoustic camera? For compressed air leak detection alone, the ROI is typically measured in months. A single quarter-inch air leak costs $2,500–$8,000 per year. Most industrial facilities have dozens to hundreds of leaks. An acoustic camera that helps you find and fix these leaks can pay for itself in the first survey. Can acoustic cameras detect gas leaks other than compressed air? Yes. Acoustic cameras can detect any pressurized gas leak that produces turbulent flow noise — including nitrogen, oxygen, hydrogen, natural gas, and refrigerants. The frequency characteristics may vary by gas type, but the detection principle is the same. Need help choosing the right acoustic camera for your application? Contact CRYSOUND for a personalized recommendation based on your specific requirements.

What Is an Anechoic Chamber? An anechoic chamber is a room designed to completely absorb sound reflections. The walls, ceiling, and (in a full anechoic chamber) the floor are lined with wedge-shaped foam or fibreglass absorbers that prevent sound waves from bouncing back into the room. The result is a controlled acoustic environment that simulates free-field conditions — as if the sound source were suspended in open air with no surfaces nearby. This matters because most acoustic measurements — sound power, directivity, frequency response — require a known, reflection-free environment to produce repeatable, standards-compliant results. Without it, room reflections contaminate the measurement, making results dependent on the specific room rather than the product being tested. Full Anechoic vs Semi-Anechoic (Hemi-Anechoic) Chambers Feature Full Anechoic Semi-Anechoic (Hemi-Anechoic) Absorbing surfaces All 6 surfaces (walls, ceiling, floor) 5 surfaces (walls + ceiling); floor is reflective Floor Wire mesh or perforated metal grid suspended above absorbers Solid, load-bearing concrete or steel Acoustic condition Free-field (no reflections from any direction) Free-field over a reflecting plane Load capacity Limited — cannot support heavy equipment directly Can support vehicles, machinery, industrial equipment Primary standards ISO 3745 (precision sound power) ISO 3744 (engineering sound power), ISO 3745 Typical use Microphone calibration, loudspeaker characterisation, hearing research Automotive NVH, product noise testing, industrial machinery Cost Higher (floor treatment adds significant cost and complexity) Lower (no floor treatment needed) In practice, about 80% of industrial acoustic testing uses semi-anechoic chambers because most test objects — cars, appliances, compressors, power tools — are too heavy for a suspended wire-mesh floor. What Standards Require an Anechoic Chamber? ISO 3745 — Precision Sound Power Measurement The gold standard for sound power determination. Requires either a full anechoic or hemi-anechoic chamber qualified to meet strict free-field deviation limits across the frequency range of interest. The chamber must demonstrate that the inverse-square law holds to within ±1 dB at the measurement positions. Typical cut-off frequency: 80–200 Hz, depending on chamber size and wedge depth. Below this frequency, the chamber no longer behaves as a free field. ISO 3744 — Engineering Sound Power Measurement Less stringent than ISO 3745 but still requires a hemi-anechoic environment. Allows for environmental corrections when the room is not perfectly anechoic, making it practical for production-floor test cells that approximate (but do not perfectly achieve) free-field conditions. ISO 26101 — Qualification of Free-Field Environments Defines how to verify whether a room actually meets free-field requirements. This is the standard used to “qualify” an anechoic or hemi-anechoic chamber — confirming that its acoustic performance matches what is claimed. Other Standards ECMA-74: IT equipment noise measurement (uses ISO 3745 or ISO 3744 as the underlying acoustic method) ANSI S12.55 / S12.56: North American equivalents of ISO 3744/3745 ISO 11201–11205: Various sound pressure level determination methods, some requiring free-field conditions Key Design Considerations 1. Chamber Size and Usable Volume The physical dimensions determine the lowest usable frequency. A general rule: the chamber must be large enough that the distance between the sound source and each measurement microphone is at least one wavelength at the lowest frequency of interest. For a 100 Hz cut-off, the minimum source-to-microphone distance is approximately 3.4 metres, which means the chamber’s internal dimensions (excluding wedges) should be at least 7–8 metres per side for a hemi-anechoic chamber. 2. Wedge Absorbers The depth of the absorbing wedges determines the low-frequency performance. Deeper wedges absorb lower frequencies: Wedge Depth Approximate Low-Frequency Cut-off 200 mm ~500 Hz 500 mm ~200 Hz 1000 mm ~80–100 Hz Wedge materials include melamine foam (lightweight, fire-retardant) and fibreglass (better low-frequency absorption but heavier). 3. Background Noise An anechoic chamber must also be well-isolated from external noise. The ambient noise level inside the chamber (with no source operating) should be at least 6 dB — and preferably 15 dB — below the sound pressure level generated by the test object at the measurement positions. This typically requires a chamber built with multiple layers of massive construction (concrete, steel) and vibration-isolated mounting to prevent structure-borne noise transmission. 4. Vibration Isolation For NVH testing (especially automotive), the chamber floor may include vibration-isolated foundations or air-spring mounting systems to prevent road-simulator or dynamometer vibrations from coupling into the acoustic measurement environment. What If You Do Not Have an Anechoic Chamber? Not every organisation can invest $500K–$2M+ in a purpose-built anechoic facility. Several practical alternatives exist: Sound Intensity Method (ISO 9614) Sound intensity measurements are inherently less sensitive to room reflections because intensity is a vector quantity — it distinguishes between outgoing sound (from the source) and incoming sound (reflections from room surfaces). This allows sound power determination in ordinary rooms without anechoic treatment. Trade-off: Requires specialised intensity probes and more complex measurement procedures. Acoustic Test Boxes For small products (electronics, components, transducers), a desktop-sized acoustic test box provides a controlled, low-noise environment that approximates anechoic conditions within a defined frequency range. These are significantly cheaper than a full chamber and can be placed directly on a production line. CRYSOUND offers a comprehensive range of acoustic test chambers designed for different testing scenarios: CRY723 Pneumatic Acoustic Test Chamber — A compact, shell-type test box ideal for smartphones and wireless wearables. Combine two CRY723 units with a CRY6151B analyzer for complete audio, ENC, and ANC measurements. CRY725 Pneumatic Acoustic Test Chamber — Designed for larger wireless devices such as laptops and walkie-talkies. Compatible with comprehensive testers and vector network analyzers. CRY7865 Pneumatic Acoustic Test Chamber — A high-performance drawer-style chamber with both acoustic isolation and RF shielding, ideal for production line audio and noise measurements of wireless electronic devices. CRY7412 Ultra-Quiet Chamber — An ultra-quiet chamber for testing very quiet sounds in noisy environments. Features a unique double-shell design for superior noise isolation. All models support pneumatic operation for fast, repeatable DUT loading on production lines — a practical alternative when a full anechoic chamber is not justified by the application. Portable Acoustic Arrays Modern acoustic imaging cameras can identify and localise noise sources in situ — in the factory, on the production line, or in the field — without any anechoic treatment. While not a substitute for standards-compliant sound power measurements, acoustic imaging enables rapid noise source diagnosis that previously required dedicated chamber time. The CRY8500 Series SonoCam Pi Acoustic Camera, is a portable acoustic imaging camera that delivers real-time sound source visualisation — ideal for R&D engineers working on noise source identification in automotive NVH, industrial equipment, and consumer electronics. In-Situ Sound Power (ISO 3744 with Corrections) ISO 3744 allows environmental correction factors to account for room reflections. If the correction is small (typically less than 2 dB), the measurement can be performed in a reasonably quiet industrial space without a purpose-built chamber. The SonoDAQ Pro data acquisition system combined with OpenTest software supports automated sound power calculations with environmental corrections built in — enabling standards-compliant measurements without a dedicated anechoic chamber. Frequently Asked Questions How much does an anechoic chamber cost? Costs vary widely based on size, performance requirements, and cut-off frequency. A small hemi-anechoic room for component testing may start around $100K–$300K, while a large automotive-grade full anechoic chamber can exceed $2M. For smaller products, acoustic test boxes offer similar isolation at a fraction of the cost. What is the difference between an anechoic chamber and a soundproof room? A soundproof room blocks external noise from entering but does nothing about internal reflections. An anechoic chamber both blocks external noise and absorbs internal reflections, creating a free-field environment for precision measurement. Can I do acoustic testing without an anechoic chamber? Yes. Depending on your application, alternatives include acoustic test boxes for small products, sound intensity methods (ISO 9614), portable acoustic imaging cameras like the CRY8500 SonoCam Pi, and in-situ measurements with environmental corrections using systems like SonoDAQ Pro. What frequency range does an anechoic chamber cover? The usable frequency range depends on the wedge depth and chamber dimensions. Most chambers are effective from their cut-off frequency (typically 80–200 Hz) up to 20 kHz or beyond. Below the cut-off, the chamber no longer provides adequate absorption. How is an anechoic chamber qualified? Chamber qualification follows ISO 26101, which verifies that the inverse-square law (sound pressure decreasing by 6 dB per doubling of distance) holds within specified tolerances at the measurement positions. Conclusion Anechoic chambers remain the gold standard for precision acoustic measurement — but they are not the only option. Understanding what your application truly requires helps you choose the right solution, whether that is a full anechoic room, a compact acoustic test chamber, or an in-situ measurement approach. At CRYSOUND, we provide the full spectrum: from purpose-built anechoic chambers to portable acoustic test boxes and advanced measurement systems — so you can get accurate results regardless of your facility constraints. Contact us to discuss which solution fits your testing requirements.