Self-Noise (Noise Floor)
Definition
The electrical noise inherent in a microphone circuit and capsule, measured in dB(A) equivalent input noise. Different microphone types have characteristic noise floors: MEMS microphones used in smartphones typically exhibit 58 to 65 dB(A) EIN; high-quality condenser microphones achieve below 20 dB(A).
- Unit
- dB(A) equivalent input noise
- MEMS smartphone microphones
- Typically 58 to 65 dB(A) EIN
- High-quality condenser microphones
- Below 20 dB(A)
Common questions
Why does self-noise matter when authenticating a recording?+
The characteristic noise floor of a recording can help indicate what type of microphone captured it, which is one factor an audio examiner weighs when checking whether a recording is consistent with its claimed source device.
Can self-noise be removed by later noise reduction processing?+
It can be reduced but rarely eliminated cleanly, and aggressive noise reduction leaves its own processing artefacts, so an examiner can often still detect that filtering was applied even after the original noise floor is suppressed.
Related terms
- Double Compression
- The condition in which a video has been encoded at least twice through a lossy codec. The term is also used loosely...
- MEMS Microphone
- A Micro-Electro-Mechanical Systems microphone: the capsule type used in virtually all modern smartphones and tablets. MEMS microphones have a characteristically flat midrange...
- Psychoacoustic Masking Model
- The perceptual model used by lossy codecs such as MP3 and AAC to decide which frequency components can be discarded or coarsely...
- Quantisation Noise
- The distortion introduced when a continuous audio signal is rounded to discrete digital values. Lossy codecs concentrate quantisation noise at predictable frequency...
- Spectral Fingerprint
- The characteristic frequency response profile of a recording device, including roll-off curves, resonance peaks, and self-noise level. Comparing a recording's spectral fingerprint...