STILL / FIELD NOTES 01

Using an iPhone as a sound meter: a practical starting point

An iPhone can help you explore sound and compare recordings of measurement levels. The useful first question is what the app is measuring: digital microphone level, or sound pressure supported by a reference adjustment. In Still, an unadjusted reading is dBFS.

September 8, 2026 · Arve Tech, maker of Still

Set up before pressing Start

Keep the microphone clear, place the phone consistently and choose one weighting and response setting. Write down the device, position, source and duration so you can repeat the observation. Touching the case, wind and a changed microphone route can affect the result.

Keep the claim as small as the evidence

A stable display is not proof of calibrated accuracy. Use the same setup for exploratory comparisons, and do not compare unadjusted dBFS values with environmental dBA limits. A certified assessment needs suitable equipment and a defined measurement procedure.

Try a repeatable approach

1. Choose a stable position and keep hands away from the microphone.
2. Start a session long enough to include the sound's normal variation.
3. Save the conditions alongside the result before changing anything.

Source and scope

Apple: audio metering in dBFS

Measurement guidance is educational. Still is not a certified sound level meter and does not establish medical, legal or workplace-compliance conclusions. App-specific statements describe version 1.0.0, currently awaiting App Store review.