EFX may refer to: EFX (show), a Las Vegas show EFX (album), an album of the show Enerflex Systems, a Canadian company listed as EFX on the Toronto Stock Exchange Equifax, a U.S. consumer credit re
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x19d61a322a14ec648b1fcdaba75c04835a5c698c615c2fd725c9efa8be43822b. Chain 2 (Bitcoin): anchored in block 953778 (2026-06-15T11:57:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/aa6419b8-f610-49e9-9d5a-70993a40c24b.json and https://artists.proofprofile.net/proofs/artist/aa6419b8-f610-49e9-9d5a-70993a40c24b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
200 Sound Effects (The Ultimate Library: Sounds & Jingle)
Sound Effects, Vol. 4 (Heartbeat, Seagulls, Telephone, Hammer, Insects and More...)
Sound Effects, Vol. 1 (Water, Police, Radio, Tennis, Motor Bike and More)
EFX - Sound Effects, Vol. 3 (Footsteps, Sneeze, Laugh, Birds, Screams and More)
Sound Effects, Vol. 2 (Applause, Cartoons, Cry, Boing!)