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24-Sound Reference Library in dB Pulse
The free Sound Reference Library gives 24 familiar benchmarks to help interpret a live reading. Each level is approximate and should be read as a comparison, not a measurement of the named source in your room.
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| Question | Answer | Context |
|---|---|---|
| Availability | Free | In the iPhone app |
| Metering | Foreground only | Stops when app leaves foreground |
| Next step | Start a session | Keep date and place with the reading |
Read the live comparison
When the app shows a live estimate, a nearby reference label can provide a quick mental picture. At one level you might see '≈ Heavy truck'. That means the number is near a typical benchmark in the library; it does not identify the sound your microphone heard. A fan, vehicle or group conversation can overlap in level at different distances.
This distinction matters because the same source can vary dramatically. A truck seen from across a road differs from one beside your ear. So does a whisper near a phone versus one several metres away. Start with the numeric reading, then treat the label as an everyday analogy.
Explore all 24 benchmarks
The Tools area contains a Reference levels sheet with the full ladder, beginning with a quiet breathing example and reaching loud impulse examples. It also marks the NIOSH 85 dBA occupational reference and a pain-threshold marker at 130 dB. Those markers describe different ideas. NIOSH’s recommended exposure limit is an eight-hour workday average, while a pain threshold is not a safe-exposure boundary.
The nearest benchmark also appears on a saved session’s peak detail. That can help when you revisit a measurement weeks later and no longer remember what a bare number felt like. Keep the session’s location and conditions attached; the label alone is too broad to explain what happened.
Make a fair comparison
Hold the phone at a consistent position and keep the microphone unobstructed. Choose the same weighting and response when comparing two situations. If you are trying to assess a change, record the before and after positions, room state and duration. A change from 60 to 70 dB represents a tenfold change in sound intensity under the logarithmic decibel scale; perceived loudness is a separate human response.
Do not compare a brief peak with a sustained average as if they were the same thing. The library is meant to help recognition, while the chart, session Leq and peak labels answer more precise questions. For hearing-risk questions, add how long you heard the sound and use the noise dose guide.
Keep the reference honest
The reference values are typical approximations, not laboratory certifications of every named object. Your phone also needs comparison with a trusted meter for a meaningful absolute calibration. If a reading looks surprising, first check the microphone opening, case, orientation and app settings, then repeat at the same location.
For a workplace assessment, legal record or medical concern, use the relevant qualified procedure. The library remains useful for conversation and first-pass comparisons, especially when you need to explain why a change in level deserves a closer look.
Sources
Phone and browser readings are estimates. For formal decisions, use the specified equipment and procedure; see the accuracy notes.
Try the next check
Noise dose calculator can help with this question. See the matching dB Pulse feature.