What is -25 dB Signal to Noise Ratio (S/N)?
If a sound intensity is reduced by one-half it is equivalent to a change of -3 dB. A signal/ noise ratio of -25 dB means the sound source intensity is literally about 300 times lower than the background noise intensity.What does this mean, can you give an example? Imagine a soloist singing, the sound power is assumed to be unity. Behind the soloist is a choir, each member is also singing with the same unit intensity. If the choir has nine members singing, the signal to noise ratio will be -10dB. The human ear could just about pick out the soloist with this overall level of background noise. So what is -25dB equivalent to? If the number in the choir is increased to about 300, all singing with the same intensity, the soloist would be completely masked by the background noise. The signal to noise ratio is now about -25dB. BatScan can both locate and measure the sound intensity of the soloist. The human ear is an extraordinary instrument – but the BatScan system has greater sensitivity and
