- The signal-to-noise ratio in dB between a defined useful signal and the A-weighted self-noise (equivalent noise level) of the microphone
- Reference useful signal: 1 kHz sine wave with 1 Pa sound pressure (corresponds to 94 dB SPL)
- Signal-to-Noise Ratio = 94 dB-SPL - equivalent noise level (A-weighted)
- After a large round of measurements in 2018 with external partners, the values may differ from older values. The reason for this is the continuous material and electronic component changes of the microphones in the last years and decades.