On the decibel (dB) scale, negative numbers are used to represent measurements that are lower or quieter than a reference level. The decibel scale is a logarithmic scale that is widely used to express relative differences in intensity or power, particularly in the fields of acoustics and electronics.
In acoustics, negative decibel values indicate a decrease in sound pressure level (SPL) compared to a reference level. For example, if a sound has an SPL of 0 dB, a sound with an SPL of -10 dB would be 10 decibels quieter than the reference level. Similarly, if the reference level is, for instance, 70 dB, a sound with an SPL of 60 dB would be 10 decibels quieter than the reference level.
Negative decibel values can also be used to represent attenuations or losses in electronic systems. In this context, a negative dB value indicates a decrease in signal strength or power. For instance, if a signal is attenuated by -3 dB, it means the signal has been reduced by 3 decibels.
It's important to note that the decibel scale is logarithmic, which means that a 3 dB change represents a doubling or halving of power or intensity. Therefore, negative decibel values indicate reductions or decreases in comparison to the reference level.