Technical Activity Log · March 2026
Low-latency speech synthesis pipeline
- Claiming company
- Northstar Voice Systems Inc. (fictional)
- Project code
- NVS-01
- Evidence month
- March 2026 · based on original commit dates
- Draft created
- April 1, 2026 · written after the dated work
01
Objective
Determine whether clause-level audio streaming could reduce time-to-first-audio below 800 ms without creating audible discontinuities at chunk boundaries.
02
Technological uncertainty
The team could not determine from generally available approaches whether shorter synthesis windows would preserve enough linguistic context for stable prosody. Sentence-level buffering preserved quality but exceeded the latency target; token-level streaming reduced latency but produced unstable joins.
03
Testable ideas and investigation
| Testable idea / approach | Method | Result / learning |
|---|---|---|
| H1. Clause-boundary chunking will reduce perceived latency below 800 ms without detectable join artifacts. | Implemented the splitter and compared it with the sentence-level baseline using the existing latency harness (a3f81c2e, 9d04bb71). | p95 first-audio decreased from 1.9 s to 740 ms, but clause joins caused a prosody regression. The joiner was reverted (f81d3a55). H1 was only partially supported. |
| H2. An adaptive buffer can retain H1's latency gain while adding context only around ambiguous boundaries. | Added a feature-gated adaptive buffer and replayed the same benchmark corpus (61be20aa). | The experiment opened a viable direction, but the available repository evidence did not contain a complete quality result. The draft would carry a VERIFY marker until the company supplies or removes that assertion. |
04
Advancement attempted
The work established that clause boundaries alone were not a sufficient streaming unit for this pipeline and narrowed the next investigation to context-sensitive buffering. The failed joiner and its revert are retained as evidence of the path ruled out—not rewritten as a successful feature story.
05
Repository evidence
| Commit ID (SHA) | Message | Lines changed |
|---|---|---|
| a3f81c2e | Add clause-boundary streaming splitter | +184 / −31 |
| 9d04bb71 | Benchmark clause vs sentence chunking | +96 / −12 |
| f81d3a55 | Revert cross-clause joiner after prosody regression | +8 / −74 |
| 61be20aa | Gate adaptive buffer behind latency experiment flag | +129 / −18 |
Real exports also include a spreadsheet-friendly evidence file, the source of each record, earlier versions, and file fingerprints that reveal changes. Source code and diffs are not stored.
06
Hours — controlled by the company
Waiting for hours from company records
T661.ai does not convert commit activity into claim hours. The company first enters hours from payroll, timesheets, calendars, or another named record. Only then can it view a GitHub activity comparison and confirm or explain the amount.
07
Checks required before creating the final log
- Every cited commit ID exists in this month's evidence.
- One unsupported H2 result remains and must be verified or removed.
- Hours and source are not yet declared or confirmed.
- The final log cannot be created until every required item is fixed.