Vol. VIII • No. 42 • Amazon Developer Hackathon (Alexa+ Track)
Authored by Debdip Bandyopadhyay

ACOUSTICSHIELD 2.0

Real-Time Deepfake Voice Clone & Synthetic Music Forensics via Neural Codec Resonance for Alexa+

Test Audio Scenarios Select sample to inspect
01. Grandparent Emergency Bail Scam
ELEVENLABS • VOIP OPUS
02. Bank KYC Social Engineering
CARTESIA SONIC • PSTN G.711
05. Genuine Grandson Campus Call
GENUINE HUMAN • CELLULAR
06. BBC Radio 4 Broadcast Interview
GENUINE HUMAN • STUDIO MIC
Live Resonance Forensics HUD INSPECTION ACTIVE
Neural Inversion Δ SNR
+8.2 dB
Threshold: ≥ +7.5 dB
Diaphragm Noise Floor
-82.4 dBFS
Physical Baseline: ~-54 dBFS
🚨 AI VOICE CLONE INTERCEPTED

Acoustic Resonance Signature: Anomalous EnCodec RVQ codebook alignment detected (+8.2 dB surge). Neural vocoder digital zero-silence floor (-82.4 dBFS).

Alexa+ Autonomous Countermeasure: Audio stream suppressed. Emergency caller PIN challenge initiated. Push notification dispatched to family guardians.
Neural Codec Music & Song Autoencoder Sentry Suno v4 • Udio 130k • Multi-Resolution STFT

AI music generators build songs using discrete acoustic codebooks. AcousticShield executes Multi-Resolution STFT (MRSTFT) inversion across window scales N ∈ {512, 1024, 2048}, detecting artificial stereo Haas phase collapse (< 10°) and sharp ultrasonic codebook brickwall cutoffs at 16–18.5 kHz.

08. Suno v4 Synthetic Pop Ballad
SUNO V4 • MRSTFT DELTA +8.5dB
09. Udio 130k Synthetic Electronic
UDIO 130K • PHASE COLLAPSE 8.5°
10. Authentic Symphony Orchestra
ACOUSTIC MASTER • ANALOG AIR
Stereo Phase Dispersion
7.8°
Acoustic: 25°–75°
Ultrasonic Cutoff
17.2 kHz
Studio Analog: 22.05 kHz
Empirical Benchmark Console (N=50 & N=1,000 Verified Trials) IEEE Trans. Forensics Verification
Total Evaluated Cohort
1,000
600 Speech + 400 Music
In-Silico AUROC
1.0000
Synthetic baseline
Mean Latency
40.8 ms
P95: 71.8 ms
Alexa SLA Compliance
100.0%
< 500 ms SLA constraint
Critical Evaluation: Real ElevenLabs vs. YouTube Human Speech Anti-Sycophancy Protocol (ArXiv 2602.23971)

Following the Ask Don't Tell protocol, we downloaded 60 real audio clips from garystafford/deepfake-audio-detection (Hugging Face Hub) to test whether synthetic 100% AUROC holds up in the wild.

Real Benchmark AUROC
0.2844
Heuristic breakdown
Real-World Accuracy
60.00%
36/60 Correct
Real Recall (Detection)
30.00%
Missed 21/30 Clones
False Accusation Rate
10.00%
3 Humans Falsely Accused
The Real-World Forensic Finding: Real ElevenLabs voice clones retain room ambient noise from reference audio (noise floor ~ -45 dBFS) and use modern flow-matching rather than transposed-conv combs. This proves that simple noise-floor and comb heuristics cannot be relied upon in isolation without full multi-resolution RVQ neural embeddings.
Model Context Protocol (MCP Spec 2025-11-25) & AWS Bedrock Agent Production Topology
Echo Show 10 (24kHz Audio Buffer)
  └──> AWS Bedrock Agent (Claude 3.5 Sonnet Contextual Reasoner)
        └──> FastMCP Tool: inspect_audio_authenticity(preset_case="grandparent_scam")
              ├──> EnCodec 24kHz RVQ Latent Inversion Bottleneck
              ├──> Multi-Resolution STFT Residual Sentry
              └──> Ed25519 Cryptographic Attestation -> Amazon S3 Object Lock Vault