In-Cabin Noise Monitoring with OBD Data
When an interior sound comes and goes, it can be hard to describe. OBD CAN records phone-microphone sound levels and, when available, pairs them with vehicle speed and engine RPM. The report organizes observations by driving condition; it does not locate a mechanical fault.
What the recording shows
The app displays cabin sound level and records readings. Reports can show duration, sample count and statistics, plus speed-band or RPM comparisons when enough OBD samples exist. These can show whether recorded sound varies with a reported speed or engine-speed range. A phone is not a calibrated sound meter; placement, case, windows, ventilation, passengers and road surface affect readings.
How to make a recording
- Connect a compatible BLE OBD2 adapter, sign in and secure the phone. Noise analysis requires Premium membership.
- Open Noise Detection and grant microphone permission. A live OBD connection supplies available speed and RPM context.
- For a quieter baseline, close windows, switch off audio and turn off the heater or fan. Keep the phone in a consistent position.
- Tap Start Detection, then Stop Detection when ready. Do not handle the phone while driving; ask a passenger or stop safely.
- Review the summary and available speed or RPM comparison charts. Saved sessions can be revisited from diagnostic history.
Illustrative example: document an intermittent rattle
Suppose a driver hears a trim rattle mainly on rough roads. With the phone secured, they record a trip safely and review the summary and speed-band chart. If a similar pattern appears in another comparable session, share both observations with a repair shop and ask for an inspection. The sound pattern cannot pinpoint trim, wheel, suspension or engine parts, or distinguish a defect from road noise or microphone placement.
Compatibility and limits
Microphone permission, a compatible connected BLE OBD2 adapter, sign-in and Premium membership are required. OBD speed and RPM appear only when readable; otherwise comparisons may be absent. Phone microphones vary, so dB values are relative observations, not certified measurements or diagnosis.
Frequently asked questions
Does the app automatically locate the noise?
No. It records sound level and can compare it with available speed or RPM context. It does not identify a component or pinpoint where the sound originates.
Can I use the result as a calibrated dB measurement?
No. Phone microphones and placement differ. Use the values to compare similar recordings, not for compliance or professional acoustic measurement.
Why is there no speed or RPM chart?
The vehicle or adapter may not provide those readings, or there may not be enough valid samples for a comparison. The sound recording can still contain its own summary.