Sample Acoustic Data Analysis Report

ITAR Screen (Required)

ITAR Screen Result = CLEAR
Basis: The upload is a short, single-channel WAV recording of an industrial motor sound/vibration signal with no apparent military/defense identifiers, controlled system design details, or performance/implementation data tied to weapons/munitions. (If this recording came from defense/aerospace hardware or a controlled test article, tell me before we proceed further.)

Data Type Detected

A) Raw waveform time series (WAV audio)

  • Duration: 10.0 s

  • Sample rate: 44,100 Hz

  • Channels: 1 (mono)

  • Bit depth: 16-bit PCM

  • Clipping: None detected (0.0%)

Executive Summary

This 10-second recording shows a strong low-frequency tonal/periodic component plus high-frequency (HF) energy with bursty amplitude modulation. The HF “envelope” behavior (a common bearing-fault cue when a defect excites resonances) is elevated, consistent with bearing roughness/incipient defect or other sources that create intermittent HF excitation (rubbing, looseness, impacting, electrical excitation coupling into structure).

Overall data quality: good (no clipping; adequate bandwidth).
Primary limitation: no RPM/tach, sensor type, mounting location, or baseline “healthy” reference.

Data Characteristics (Engineering Checks)

  • Peak amplitude (relative, not calibrated SPL/accel): 0.95 FS

  • RMS level (relative): 0.345 FS

  • Crest factor: 2.75 (not extremely impulsive in raw waveform)

  • HF envelope kurtosis ≈ 13.5 (high → suggests intermittent HF bursts, often seen with bearing defects when bandpassed + demodulated)

Key Spectral Observations (Relative, Not Calibrated)

Prominent components in the spectrum:

  • Strong peak near ~32.3 Hz with harmonics (≈ ~91.5 Hz, ~150.7 Hz, etc.)

    • Interpretation: could be shaft rotational rate ~32 Hz (~1938 RPM) or a strong subharmonic/structural response.

  • Clear component near ~59–60 Hz

    • Interpretation: likely electrical line frequency (or mechanical driven at/near 60 Hz).

  • HF resonance/tonal feature around ~2.9 kHz, with additional broadband HF energy.

Envelope (demodulated HF band 1–8 kHz) shows strong modulation peaks at:

  • ~120 Hz and harmonics (~240, ~360, ~480 Hz)

    • Interpretation: consistent with 2× line frequency / rectification effects and/or strong periodic forcing; can also appear when HF bearing resonance is amplitude-modulated by electrical/rotational phenomena.

Detected Events

No discrete start/stop “events” were cleanly segmentable in only 10 seconds; behavior is mostly continuous with intermittent HF burstiness.

Event Group 1 — Continuous tonal + modulated HF bursts

  • Duration: 10 s

  • Dominant low-frequency: ~32 Hz (plus harmonics), plus ~60 Hz

  • HF content: resonance-like band around ~2.9 kHz with bursty envelope

  • Likely source class: Electric motor with suspected bearing roughness/defect (or mechanically similar fault producing HF bursts)

Confidence: 70% (Moderate)
Why not higher: RPM unknown, sensor/coupling unknown, and electrical excitation can mimic some modulation patterns without a bearing defect.

Classification Summary Table

Group Source / Condition (Conservative)ConfidenceEvidence1Electric motor w/ possible bearing defect/roughness (or impacting/rub)70%HF envelope burstiness (high kurtosis), HF resonance band, low-frequency periodicity + harmonics

Limitations & Assumptions

  • No calibration (cannot report SPL, Pa, or g; only relative full-scale).

  • No RPM/tach or motor details (can’t compute BPFO/BPFI/BSF/FTF defect frequency matches).

  • Unknown sensor type & mounting (airborne mic vs accelerometer changes interpretation significantly).

  • Only 10 seconds (short for robust statistics; limited operating-state variety).

Confidence depends heavily on sampling rate, sensor type (mic/hydrophone/accelerometer), placement/coupling, gain, clipping, noise, channel geometry, medium, codecs/compression, and completeness. Accuracy can exceed 95% in optimal conditions, but this clip is not fully “optimal” due to missing metadata and lack of tach/baseline.

Recommendations

  1. Add tach/RPM (or VFD command frequency) time-sync’d to the recording. This is the single biggest unlock for bearing-defect frequency confirmation.

  2. Record 60–180 seconds at steady-state and during load changes (bearing faults often scale with load).

  3. If feasible, capture a healthy reference from the same motor/sensor placement for A/B comparison.

  4. Prefer a structure-borne accelerometer mounted on the bearing housing (stud or strong adhesive) over an airborne mic for bearing diagnosis.

  5. If you can’t add tach: provide motor pole count + supply frequency and whether there’s a gearbox/belt—I can still bound likely shaft speed and interpret the harmonics more defensibly.