the property of a system that enables it to be “tuned” to respond better to certain frequencies than to others. The degree of selectivity of such filtering is sometimes specified as Q, which is the center or best frequency of a filter divided by its bandwidth: Higher values of Q correspond to higher frequency selectivity. The frequency selectivity of the auditory system is a fundamental aspect of hearing and has been a major research theme for many decades. Also called bandwidth selectivity. See auditory filter; critical band; tonotopic organization; tuning curve.