Speech Intelligibility Index (SII) Pro

Speech Intelligibility Index

0.000

0.0% Equivalent

Poor Intelligibility

Measurement Accuracy / Confidence 0.0%

Rating: Engine Idle Awaiting stream activation

Local Device Microphone Auto Detecting...

Host Device Profile: Detecting...

Audio Interface Type: Hardware Input

Acoustic Transfer: Calibrated 48 kHz / 24-bit

Standard Vocal Effort 62.3 dB SPL

Acoustic Analysis Mode

Sensitivity / Mic Gain Trim +0.0 dB

Focus Metric Readout

Acoustic Simulation Generator

1/3-Octave Critical Spectrum Levels (dB/Hz)

160 Hz - 8000 Hz

Hover or tap any frequency band above to inspect physical spectrum levels.

Measurements, 18-band spectral telemetry, and real-time accuracy diagnostics stored in three isolated IndexedDB instances.

00:00:00

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Session summaries, smoothed SII, raw metrics, vocal effort, and acoustic condition ratings.

0 frames

Batched 18-band spectral telemetry: E_i, D_i, SNR_i, A_i, and contributions.

0 logs

Real-time accuracy %, mic fidelity, browser WebRTC DSP flags, headroom, and uncertainty budget.

Band	Center Freq (Hz)	Bandwidth Δf (Hz)	10·log₁₀(Δf)	Weight (I_i)	Speech U_i (dB/Hz)	Threshold X_i (dB/Hz)