# Module: Communication model (voice) > Canonical version. Swedish: [communication-model.sv.md](communication-model.sv.md). ## Core principle **The user speaks, the system writes.** The system uses voice-to-text for all spoken input. The technician should never have to type on a keyboard while work is in progress. No voice agent: the system does not hold a running spoken conversation, does not read long answers aloud, and does not try to imitate a human conversation. The communication is **speech in, text out**. ## Important design principle > All voice is treated as an input method, not as a separate interface. All logic in the system is built on text. Voice-to-text is only a way of producing that text. That makes the solution easier to maintain, easier to search, easier to export, and easier to develop further with new models in the future. ## Workflow 1. The technician presses the microphone: *"I've measured between pin 14 and ground. I get 12.4 volts."* 2. Voice-to-text transcribes the speech. 3. The transcribed text is sent to the model as an ordinary text request. 4. The answer always comes back in writing: *Verified: supply voltage present at pin 14. Next step: check the ground connection at pin 7.* ## Why this choice? - it works better in noisy workshops, - it produces a permanent text log with no extra step, - it makes the history easy to search, - it reduces the risk of misunderstanding compared with a continuous spoken conversation, - it suits cases where several technicians work on the same job. ## Push-to-talk (PTT) Voice input works on a push-to-talk basis. The app listens **only** while the user actively holds the microphone button, or after they have started an explicit recording. No background listening. No automatic activation. ### Flow 1. The user holds down the microphone button (or presses a clear "Record" button, depending on the platform). 2. Recording starts immediately. 3. The app shows clearly that recording is in progress: a red indicator, a timer, a level meter, and the text "Recording". 4. The speech is transcribed in real time — the user watches the text appear and gets immediate feedback on whether the speech was understood correctly. 5. When the recording ends, the transcribed text is shown in an **editable** text field. 6. The user can accept, edit or re-record. 7. **Only when the user confirms** is the text sent onward and saved to the work log. ### Editing before sending The transcription is always editable. Common corrections: registration numbers, serial numbers, component designations, personal names, technical terms. **"Send" never happens automatically.** The technician always gets a quick chance to correct the transcription before it becomes part of the permanent work log. That reduces the risk of incorrect registration numbers, component designations and measured values. ### No hidden functionality The user must always be able to see: - when recording is in progress, - when it has ended, - what will be sent, - what has actually been saved. There must never be any doubt about when audio is being recorded or when information is being sent. ## Automatic record keeping Every transcribed sentence automatically becomes part of the work log: ``` 08:14 "Measured voltage between pin 14 and ground. 12.4 volts." 08:14 System: Supply voltage verified. 08:15 "Relay doesn't click." 08:15 System: Check the control signal to the relay. ``` Everything is saved without the technician having to type a single line. ## Hands-free working The app is optimised for busy or dirty hands. During a normal case the user should be able to identify the object with the camera, photograph components, dictate observations, be shown the next step and carry on working — without typing manually. The interface has to work with gloves, dirty hands, strong sunlight, noise and vibration; the microphone button is large, easy to hit and gives clear visual feedback.