Support
Frequently asked questions, known limitations and system requirements for Hertzio.
Frequently asked questions
Is sound recorded?
No. The microphone listens only when turned on; sound is analysed in memory in real time and is never recorded, stored or sent anywhere. Only the spectrum curves saved with "Take snapshot" are kept.
How accurate are the values?
Frequency depends on the resolution; interpolation finds the strongest frequency more finely than one frequency step. Level depends on the microphone: phone microphones are not measurement microphones. For dB SPL, compare with a known sound level meter and enter a correction.
What are A and C weighting for?
A reduces bass and treble the way the ear hears at low volume; C is close to what is heard at high volume. They are the same curves used in sound level meters. Z is flat, unweighted measurement.
Microphone permission was refused; what now?
Hertzio shows the steps for the current environment: allow it in the browser's site permissions, or with the Microphone switch in the device settings for the app, then press "Try again". Sample signals and audio files are analysed without permission.
For further questions: Contact →
Known limitations
Functions not supported in the current version.
- Phone and laptop microphones are not measurement microphones; levels and values at the extremes of the range are approximate.
- Hertzio does not record sound; the spectrogram shows only the last 10 seconds and is not stored. Only the curves saved with "Take snapshot" are kept.
- There is no separate tone or noise generator; the four sample signals play only with "Listen".
- Audio file analysis needs a format the browser can decode.
System requirements
Supported platforms and system requirements are listed in the app information. Compatibility →
Get Hertzio
Try it in the browser without installation; for continued use, purchase the version for macOS, Windows or Linux.