Sound Intensity for Product Development & NVH Engineering
Sound intensity measurement (ISO 9614) identifies dominant noise sources, ranks energy contribution paths, and validates acoustic treatments — all without requiring a special acoustic room or large anechoic chamber. Critical for automotive NVH, HVAC engineering, consumer electronics, and industrial machinery product development teams across Asia.
Why Sound Intensity for Product Development?
- Identifies individual noise sources without a dedicated anechoic or reverberant chamber
- Separates and ranks source contributions in reverberant factory and test-cell environments
- Validates acoustic treatment effectiveness at component and sub-system level
- Measures sound power directly using ISO 9614 without large acoustic rooms (ISO 3745)
- Detects acoustic weak points and flanking paths in assembled products before market release
- Quantifies noise reduction achieved by design changes — essential for development iteration
Recommended Measurement System
- Nor150 Dual-Channel Analyser — two phase-matched input channels, real-time intensity spectrum, PRI display, and sound power calculation
- Nor1290 p-p Intensity Probe — 50 Hz–10 kHz face-to-face probe with 6/12/50 mm spacer set for full frequency coverage
- NorReview Intensity Module — intensity surface maps, source ranking by frequency band, sound power summation, and ISO 9614 compliance report
Product Development Application Examples
- Automotive: door seal air leakage identification, HVAC vent tonal noise, powertrain surface radiation mapping, roof panel resonances
- Consumer appliances: refrigerator compressor noise, washing machine bearing tones, dishwasher fan and pump sources
- HVAC equipment: air handling unit and chiller sound power (ISO 9614) for CE marking and product certification
- Industrial machinery: gearbox, pump, and electric motor noise source maps for targeted enclosure design
- Data centre: server rack cooling fan noise source ranking and propagation path analysis
ISO 9614 Standard Methods
- ISO 9614-1: Discrete measurement points — grid scanning for simple, stable sources
- ISO 9614-2: Continuous scanning — sweep probe over measurement surface; most common method
- ISO 9614-3: Precision method — full uncertainty analysis for traceable sound power certification
- PRI validation: Pressure-Residual Intensity Index must be ≥ 10 dB (engineering) or ≥ 7 dB (survey) per band
Development Workflow with Norsonic
- Baseline measurement — map noise sources and rank by frequency and spatial contribution
- Treatment design — identify dominant contributors and target damping, absorber, or enclosure solutions
- Validation measurement — quantify noise reduction achieved after design change
- Certification — ISO 9614 sound power declaration for product data sheet and CE marking
Related Resources
- Sound Intensity Application & Equipment Guide
- Sound Intensity Buying Guide (ISO 9614)
- Automotive & Transportation Acoustics
- Acoustic Camera — complementary source visualization tool