{"observation":{"id":"2936e1bf-5a08-4140-8e22-568ab1ab9bae","tool":"flexclip","tool_name":"FlexClip","criterion":"sync-accuracy","criterion_name":"Sync Accuracy","criterion_definition":"The effect is timed to the specific action or object rather than playing generically across the whole clip.","criterion_evidence_type":"transformation","criterion_rank_role":"decisive","criterion_rank_role_reason":"Timing the effect to the exact action is essential to believable automated sound design. (3 of 3 judges)","scenario":"bird-nature-video","scenario_name":"Bird/Nature Video","group_tag":"auto-sfx-video-generation","scenario_description":"A video featuring a bird in frame, used to test whether generated chirping or ambient sounds sync to the specific animal and movement shown on screen.","modality":"video","input_text":null,"input_artifact_refs":[],"stresses":["sync accuracy to a visible subject","nature/animal sound matching","avoiding generic ambience that ignores timing","scene-specific audio generation"],"verdict":"failed","score":null,"score_total":null,"note":"The chirping was not tied to the bird on screen; it played generically instead of syncing to the visible animal's action.","evidence_state":"verified","source":null,"artifacts":[{"url":"https://d3epheqghktydj.cloudfront.net/research-media-bird-88b167f7f533.mp4","role":"input","alt":"Bird.mp4"},{"url":"https://d3epheqghktydj.cloudfront.net/flexclip-flexclip-bird-chirping-output-1-38d273c18780.mp4","role":"output","alt":null}],"run_id":"90451942-9055-4e8c-85e6-17c773437ed7","study_title":"Automatically Add Relevant Sound Effects to Videos","study_kind":"generation","research_task":"86b84w3x5","tested_at":null,"completeness":"input-and-output","input":{"state":"not-captured","text":null,"files":[],"modality":"video","stresses":["sync accuracy to a visible subject","nature/animal sound matching","avoiding generic ambience that ignores timing","scene-specific audio generation"]},"tool_page_slug":"flexclip","tool_url":"https://aidemos.com/tools/flexclip","permalink":"https://aidemos.com/evidence/2936e1bf-5a08-4140-8e22-568ab1ab9bae","api_url":"https://ai.aidemos.com/v1/observations/2936e1bf-5a08-4140-8e22-568ab1ab9bae"},"peers":[{"id":"ea14f7df-bcae-4c53-af53-bc37821e7b99","tool":"descript","tool_name":"Descript","verdict":"failed","score":null,"score_total":null,"note":"On the bird test, the tool failed to sync sound to the animal's actual behavior, playing bird chirping continuously for the full 10-second clip even though the bird chirped only 2–3 times.","artifact_count":1,"thumbnail":"https://d3epheqghktydj.cloudfront.net/descript-descript-bird-chirping-output-1-010b2e8aa8d8.mp4","evidence_url":"https://aidemos.com/evidence/ea14f7df-bcae-4c53-af53-bc37821e7b99"},{"id":"3c325f18-9f10-480d-b154-f10498f7f11a","tool":"fine-voice","tool_name":"Fine Voice","verdict":"struggled","score":60.0,"score_total":100.0,"note":"Even with prompt guidance, chirps did not line up with the bird's actual chirping moments; the better bird output was only about 60% satisfying.","artifact_count":4,"thumbnail":"https://d3epheqghktydj.cloudfront.net/research-media-bird-88b167f7f533.mp4","evidence_url":"https://aidemos.com/evidence/3c325f18-9f10-480d-b154-f10498f7f11a"},{"id":"423601f9-0ef6-48b2-8f30-ecbcf9624efe","tool":"kling-ai","tool_name":"Kling AI","verdict":"failed","score":null,"score_total":null,"note":"The subject-specific sound can fail to line up with the object’s on-screen behavior.","artifact_count":5,"thumbnail":"https://d3epheqghktydj.cloudfront.net/research-media-bird-88b167f7f533.mp4","evidence_url":"https://aidemos.com/evidence/423601f9-0ef6-48b2-8f30-ecbcf9624efe"},{"id":"8edf5ecc-9e2f-40ad-98a9-b81a4dd468bf","tool":"mirelo","tool_name":"Mirelo","verdict":"worked","score":null,"score_total":null,"note":"It can achieve near-perfect timing on natural footage; one variant was reported as so accurately synced that the sound effects seemed like part of the video.","artifact_count":2,"thumbnail":"https://d3epheqghktydj.cloudfront.net/research-media-bird-88b167f7f533.mp4","evidence_url":"https://aidemos.com/evidence/8edf5ecc-9e2f-40ad-98a9-b81a4dd468bf"}],"other_criteria":[{"id":"cd3e8220-fdfb-4b22-9e6d-530cae14050f","criterion":"iterative-improvement","criterion_name":"Iterative Improvement","rank_role":"context","verdict":"struggled","score":null,"score_total":null,"note":"The reviewer needed about 2–3 test runs to find one good result, indicating that rerendering did not reliably stabilize quality or alignment.","artifact_count":0,"evidence_url":"https://aidemos.com/evidence/cd3e8220-fdfb-4b22-9e6d-530cae14050f"},{"id":"7691deec-7e6d-4a0b-8a18-a08baa571de5","criterion":"output-quality","criterion_name":"Output Quality","rank_role":"decisive","verdict":"struggled","score":null,"score_total":null,"note":"The generated audio lacked depth and was not convincing on close inspection, even though it added plausible ambient bird sounds.","artifact_count":2,"evidence_url":"https://aidemos.com/evidence/7691deec-7e6d-4a0b-8a18-a08baa571de5"},{"id":"8b1d4819-6025-49a6-a216-1d3c30fa2cbe","criterion":"scene-sound-relevance","criterion_name":"Scene-Sound Relevance","rank_role":"decisive","verdict":"worked","score":null,"score_total":null,"note":"The tool can add ambient bird-and-forest audio that fits the scene context, even when the chirps themselves remain generic.","artifact_count":2,"evidence_url":"https://aidemos.com/evidence/8b1d4819-6025-49a6-a216-1d3c30fa2cbe"}],"appears_in":[{"page_type":"ranking","slug":"ai-sound-effect-generators","title":"Best AI Tools to Automatically Add Sound Effects to Videos","url":"https://aidemos.com/best/ai-sound-effect-generators","binding":"run"},{"page_type":"tool","slug":"fine-voice","title":null,"url":"https://aidemos.com/tools/fine-voice","binding":"run"},{"page_type":"tool","slug":"flexclip","title":null,"url":"https://aidemos.com/tools/flexclip","binding":"run"},{"page_type":"tool","slug":"kling-ai","title":null,"url":"https://aidemos.com/tools/kling-ai","binding":"run"},{"page_type":"tool","slug":"mirelo","title":null,"url":"https://aidemos.com/tools/mirelo","binding":"run"}],"same_scenario":[{"id":"ea14f7df-bcae-4c53-af53-bc37821e7b99","tool":"descript","tool_name":"Descript","verdict":"failed","score":null,"score_total":null,"note":"On the bird test, the tool failed to sync sound to the animal's actual behavior, playing bird chirping continuously for the full 10-second clip even though the bird chirped only 2–3 times."},{"id":"3c325f18-9f10-480d-b154-f10498f7f11a","tool":"fine-voice","tool_name":"Fine Voice","verdict":"struggled","score":60.0,"score_total":100.0,"note":"Even with prompt guidance, chirps did not line up with the bird's actual chirping moments; the better bird output was only about 60% satisfying."},{"id":"423601f9-0ef6-48b2-8f30-ecbcf9624efe","tool":"kling-ai","tool_name":"Kling AI","verdict":"failed","score":null,"score_total":null,"note":"The subject-specific sound can fail to line up with the object’s on-screen behavior."},{"id":"8edf5ecc-9e2f-40ad-98a9-b81a4dd468bf","tool":"mirelo","tool_name":"Mirelo","verdict":"worked","score":null,"score_total":null,"note":"It can achieve near-perfect timing on natural footage; one variant was reported as so accurately synced that the sound effects seemed like part of the video."}]}