This user guide explains the main controls and indicators in Sound Analyzer App. Labels and available options may vary slightly with the installed version.
1. Before measuring
Sound Analyzer App is intended for acoustic observation and learning. It does not replace an approved sound level meter. Measurement accuracy depends on the microphone, the smartphone electronics, any audio processing and calibration.
- Check microphone sensitivity in the calibration menu, ideally by comparison with a reference sound level meter.
- Disable touch sounds and audible notifications that might interfere with the measurement.
- Point the microphone towards the sound source. The screen rotation control may make the display easier to read.
- Avoid direct wind, objects close to the microphone and sound levels that could cause saturation.
2. Using the sound level meter
- Indicator selection: select between one and four acoustic indicators from the drop-down list.
- Play, Pause and Reset: start, pause or reset the measurement.
- Statistics: display minimum and maximum values on the chart for instantaneous indicators, when available.
- Chart: tap to switch between indicators. When measurement is stopped, pinch to zoom in or out.
For a simple interpretation, use LAF to follow rapid changes in sound level (a near-instantaneous reading) and LAeq for the energy-average sound level over a measurement period.
3. Using the spectrum analyzer
- First menu: select octave-band (1/1) or one-third-octave-band (1/3) analysis.
- Second menu: select A, C or Z (unweighted) frequency weighting.
- Third menu: select Fast, Slow or Impulse time weighting, or the equivalent continuous level Leq.
- Chart: pinch to adjust zoom and tap a bar to view its frequency and level.
The spectrum helps identify the frequency bands that dominate a sound and complements the overall sound level indicators.
4. Understanding the triangular indicator
The triangular indicator is normally cyan. It turns pink when the analog-to-digital converter (ADC) clips. This is not a comprehensive acoustic overload indicator: the microphone or its electronics may saturate before the ADC. Interpret high-level measurements with caution.
In spectrum analysis, flashing can also indicate that processing is not keeping up with real time. If this occurs, close other apps or switch to the less computationally demanding octave-band analysis.
5. Adjusting microphone sensitivity
Comparison with a reference sound level meter is the recommended calibration method. The calibration menu also provides a background-noise-based method, which requires additional caution when no reference instrument is available.
See the detailed microphone calibration guide for the procedure and its limitations.
6. Exporting results
After pausing a measurement, use the share button to send the calculated acoustic data to a compatible app, such as email, cloud storage or a spreadsheet. Sound Analyzer App does not record the raw audio signal.
Versions using TSV export produce tab-separated data files. Open these in a spreadsheet using a tab delimiter and UTF-8 encoding. The exact file format may depend on the installed version.
7. Understanding acoustic indicators
Frequency weightings: A, C and Z. Z denotes a nominally unweighted response over the relevant frequency range.
- LAF, LAS, LAI: A-weighted levels with Fast (125 ms), Slow (1 s) or Impulse (35 ms rise, 1,500 ms decay) time weighting.
- LCF, LCS, LCI: the same time weightings with C frequency weighting.
- LZF, LZS, LZI: the same time weightings with Z frequency weighting.
- LAeq, LCeq, LZeq: equivalent continuous levels over the observation period with A, C or Z weighting.
- LAE (SEL), LCE, LZE: sound exposure levels with A, C and Z weighting.
- LEX,8h (or LEP,d): daily noise exposure level normalized to an eight-hour reference period.
Band analysis: octave-band and one-third-octave-band results are available with the frequency and time weighting options provided by the app.
These descriptions explain the app's calculation features; they do not imply metrological conformity of the smartphone.