STIPA
The professional speech intelligibility measurement tool trusted by audio engineers, fire safety professionals, and acoustic consultants worldwide. Laboratory-grade accuracy in a portable iOS app.
Professional STI Measurement
Accurately measure Speech Transmission Index using the standardized modulation transfer function method across seven octave bands. Results you can trust for compliance documentation.
Compliance Ready
Meet IEC 60268-16:2011, NFPA 72 voice intelligibility, ANSI/ASA S12.60 classroom acoustics, and ADA accessibility requirements with certified measurement methodology.
Real-Time Analysis
Live STI value with IEC qualification display, seven octave band monitoring, modulation index visualization, and signal quality indicators for measurement confidence.
Comprehensive Reporting
Generate professional PDF reports for clients, export CSV for analysis, JSON for system integration. Include location names, notes, and timestamps in all exports.
Measurement Flexibility
Support for external calibrated microphones, adjustable measurement duration, built-in STIPA test signal generator. Works with any PA system or audio source.
Data Management
Save unlimited measurements with searchable history. Compare results across locations, track system performance over time, and analyze trends with the statistics dashboard.
Understanding STI Results
Who Uses STIPA
Fire Safety Professionals
Test voice evacuation and emergency communication systems for NFPA 72 compliance. Document speech intelligibility across all acoustically distinguishable spaces.
AV Integrators
Commission PA systems with confidence. Verify speech clarity meets client specifications and industry benchmarks. Troubleshoot with octave band analysis.
Acoustic Consultants
Assess room acoustics and their impact on speech transmission. Identify reverberation and noise issues. Provide quantitative data for remediation.
Educational Facilities
Ensure classroom audio systems meet ANSI S12.60 requirements. Document ADA compliance for hearing accessibility. Optimize learning environments.
Houses of Worship
Verify sermon intelligibility throughout the sanctuary. Optimize sound system performance for clear communication to all congregants.
System Commissioning
Document baseline performance for new installations. Provide quantitative acceptance criteria and verification reports for handover.
Key Features
Technical Specifications
Audio Processing
- Sample Rate: 48kHz
- Frequency Range: 125Hz - 8kHz
- Octave Bands: 7
Measurement
- Modulation Frequencies: 14 per IEC
- Duration: 10-60 seconds
- Standard: IEC 60268-16:2011
Input Support
- Built-in microphone
- Lightning audio interfaces
- USB-C audio interfaces
Export Formats
- Professional PDF reports
- CSV data export
- JSON for integration
Ideal For
Privacy Focused
All audio processing and STI calculations happen locally on your device. Your measurement data stays private and secure. No audio is ever transmitted to external servers.
Professional Speech Intelligibility Testing
Download STIPA today and bring IEC-compliant speech intelligibility measurement to every job site.
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