dBschaal

dBschaal, often written dB-schaal or simply dBschaal in Dutch, refers to the decibel scale used to express sound levels. It is not a separate scale of perception but a unit-based scale for ratios of sound pressure or intensity. In acoustics, the common reference for dB SPL is p0 = 20 µPa in air, where 0 dB represents the threshold of hearing. For electronic signals, dB may use references such as 1 V or 1 mW, but in practice dB SPL is the standard in sound measurement.

The formula is dB = 10 log10(I/I0) (or 20 log10(p/p0) for pressure). The logarithmic nature means that each 10 dB increase roughly corresponds to a tenfold increase in acoustic intensity, while a 3 dB change is about a doubling of sound energy.

Applications: dBschaal is used in audio engineering for level setting, in environmental noise assessments to compare measured levels against limits, and in consumer electronics for labeling and compliance. Measurement conditions, microphone placement, and weighting curves (such as dB(A)) influence reported values.

Limitations: The decibel value is a physical measure; perceived loudness varies with content and frequency. Therefore, the dBschaal is often supplemented by perceptual scales or weighting to reflect human hearing.

See also: Decibel, Sound pressure level, A-weighting, Loudness, dB(A).