{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:36LCZXVQA6USX23BVYYKLJWKE4","short_pith_number":"pith:36LCZXVQ","canonical_record":{"source":{"id":"2104.11347","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2021-04-22T23:03:23Z","cross_cats_sorted":["cs.LG","eess.AS"],"title_canon_sha256":"7d668f68a0e6075dbe63b1566817ad3e562afc0e586833443d82319cc7f85be2","abstract_canon_sha256":"b3bd16f06ae99f9089f7aae913960228bf593875d48465797630b7a7c9800705"},"schema_version":"1.0"},"canonical_sha256":"df962cdeb007a92beb61ae30a5a6ca272db2f0174a0734bb4069232c3c1d07f8","source":{"kind":"arxiv","id":"2104.11347","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2104.11347","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"arxiv_version","alias_value":"2104.11347v2","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2104.11347","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"pith_short_12","alias_value":"36LCZXVQA6US","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"pith_short_16","alias_value":"36LCZXVQA6USX23B","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"pith_short_8","alias_value":"36LCZXVQ","created_at":"2026-07-05T03:11:06Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:36LCZXVQA6USX23BVYYKLJWKE4","target":"record","payload":{"canonical_record":{"source":{"id":"2104.11347","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2021-04-22T23:03:23Z","cross_cats_sorted":["cs.LG","eess.AS"],"title_canon_sha256":"7d668f68a0e6075dbe63b1566817ad3e562afc0e586833443d82319cc7f85be2","abstract_canon_sha256":"b3bd16f06ae99f9089f7aae913960228bf593875d48465797630b7a7c9800705"},"schema_version":"1.0"},"canonical_sha256":"df962cdeb007a92beb61ae30a5a6ca272db2f0174a0734bb4069232c3c1d07f8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:11:06.209601Z","signature_b64":"a9T9+9rlTkapqPqHxdSSKcemeg4JXydUt56jA5cOhErY7f3YAWduevOC1xyBejHvQJAbHMEYf196g9oSeTJzDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"df962cdeb007a92beb61ae30a5a6ca272db2f0174a0734bb4069232c3c1d07f8","last_reissued_at":"2026-07-05T03:11:06.209177Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:11:06.209177Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2104.11347","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T03:11:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"+lhGfQR068slZmwJKdG6wCdrdmMPveyx1S8baSEPkRUN4fXefb0VLZA7NQgva7PJbuePI2IcwDKotQt1nE35DQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T13:51:50.654446Z"},"content_sha256":"9ec37c915b27ceb9e178979a333f07bb9d7b15235c0cc54527f8fbe686b12caf","schema_version":"1.0","event_id":"sha256:9ec37c915b27ceb9e178979a333f07bb9d7b15235c0cc54527f8fbe686b12caf"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:36LCZXVQA6USX23BVYYKLJWKE4","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Restoring degraded speech via a modified diffusion model","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.LG","eess.AS"],"primary_cat":"cs.SD","authors_text":"Jianwei Zhang, Suren Jayasuriya, Visar Berisha","submitted_at":"2021-04-22T23:03:23Z","abstract_excerpt":"There are many deterministic mathematical operations (e.g. compression, clipping, downsampling) that degrade speech quality considerably. In this paper we introduce a neural network architecture, based on a modification of the DiffWave model, that aims to restore the original speech signal. DiffWave, a recently published diffusion-based vocoder, has shown state-of-the-art synthesized speech quality and relatively shorter waveform generation times, with only a small set of parameters. We replace the mel-spectrum upsampler in DiffWave with a deep CNN upsampler, which is trained to alter the degr"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.11347","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2104.11347/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T03:11:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"DQdfk8pM6EhS2mVi8nr5QcsaAwGujXnzN9WfLdp/RZY49zc16WD9SDUjN+Muley9GlgIRVvPTsPuZne6wUYIAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T13:51:50.655070Z"},"content_sha256":"2722d1863aab91edd85ab258906ad250370ecb0e57fc53c3018145ec148098c3","schema_version":"1.0","event_id":"sha256:2722d1863aab91edd85ab258906ad250370ecb0e57fc53c3018145ec148098c3"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/36LCZXVQA6USX23BVYYKLJWKE4/bundle.json","state_url":"https://pith.science/pith/36LCZXVQA6USX23BVYYKLJWKE4/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/36LCZXVQA6USX23BVYYKLJWKE4/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-21T13:51:50Z","links":{"resolver":"https://pith.science/pith/36LCZXVQA6USX23BVYYKLJWKE4","bundle":"https://pith.science/pith/36LCZXVQA6USX23BVYYKLJWKE4/bundle.json","state":"https://pith.science/pith/36LCZXVQA6USX23BVYYKLJWKE4/state.json","well_known_bundle":"https://pith.science/.well-known/pith/36LCZXVQA6USX23BVYYKLJWKE4/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:36LCZXVQA6USX23BVYYKLJWKE4","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"b3bd16f06ae99f9089f7aae913960228bf593875d48465797630b7a7c9800705","cross_cats_sorted":["cs.LG","eess.AS"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2021-04-22T23:03:23Z","title_canon_sha256":"7d668f68a0e6075dbe63b1566817ad3e562afc0e586833443d82319cc7f85be2"},"schema_version":"1.0","source":{"id":"2104.11347","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2104.11347","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"arxiv_version","alias_value":"2104.11347v2","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2104.11347","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"pith_short_12","alias_value":"36LCZXVQA6US","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"pith_short_16","alias_value":"36LCZXVQA6USX23B","created_at":"2026-07-05T03:11:06Z"},{"alias_kind":"pith_short_8","alias_value":"36LCZXVQ","created_at":"2026-07-05T03:11:06Z"}],"graph_snapshots":[{"event_id":"sha256:2722d1863aab91edd85ab258906ad250370ecb0e57fc53c3018145ec148098c3","target":"graph","created_at":"2026-07-05T03:11:06Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2104.11347/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"There are many deterministic mathematical operations (e.g. compression, clipping, downsampling) that degrade speech quality considerably. In this paper we introduce a neural network architecture, based on a modification of the DiffWave model, that aims to restore the original speech signal. DiffWave, a recently published diffusion-based vocoder, has shown state-of-the-art synthesized speech quality and relatively shorter waveform generation times, with only a small set of parameters. We replace the mel-spectrum upsampler in DiffWave with a deep CNN upsampler, which is trained to alter the degr","authors_text":"Jianwei Zhang, Suren Jayasuriya, Visar Berisha","cross_cats":["cs.LG","eess.AS"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2021-04-22T23:03:23Z","title":"Restoring degraded speech via a modified diffusion model"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.11347","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:9ec37c915b27ceb9e178979a333f07bb9d7b15235c0cc54527f8fbe686b12caf","target":"record","created_at":"2026-07-05T03:11:06Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"b3bd16f06ae99f9089f7aae913960228bf593875d48465797630b7a7c9800705","cross_cats_sorted":["cs.LG","eess.AS"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2021-04-22T23:03:23Z","title_canon_sha256":"7d668f68a0e6075dbe63b1566817ad3e562afc0e586833443d82319cc7f85be2"},"schema_version":"1.0","source":{"id":"2104.11347","kind":"arxiv","version":2}},"canonical_sha256":"df962cdeb007a92beb61ae30a5a6ca272db2f0174a0734bb4069232c3c1d07f8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"df962cdeb007a92beb61ae30a5a6ca272db2f0174a0734bb4069232c3c1d07f8","first_computed_at":"2026-07-05T03:11:06.209177Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:11:06.209177Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"a9T9+9rlTkapqPqHxdSSKcemeg4JXydUt56jA5cOhErY7f3YAWduevOC1xyBejHvQJAbHMEYf196g9oSeTJzDg==","signature_status":"signed_v1","signed_at":"2026-07-05T03:11:06.209601Z","signed_message":"canonical_sha256_bytes"},"source_id":"2104.11347","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9ec37c915b27ceb9e178979a333f07bb9d7b15235c0cc54527f8fbe686b12caf","sha256:2722d1863aab91edd85ab258906ad250370ecb0e57fc53c3018145ec148098c3"],"state_sha256":"c9e365e8144cf5794831608e2b09f23683eb7585e3f0b63c885c783a2e2d21da"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"98CTd3b5JaMO/TLd6q/m+Riz2xrbH7AwaDiM5vxJJdUlmjWq3FMNWl4UeHsb5p7lZs+rw2MQErNksviTQKdIDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-21T13:51:50.664193Z","bundle_sha256":"1b2b24f885373e6c1c13fe35fa561f974c571d446a6ee524f3483674197b9224"}}