Its wood may vibrate well only at certain frequencies, so some strings sound weaker than others.
The human brain is susceptible to certain frequencies that have nothing to do with volume.
Atoms typically absorb or emit light exclusively at certain frequencies.
They found that the nanotubes not only absorbed certain frequencies of infrared light, but also emitted them.
Or that our brains are so confused by certain frequencies that we can't tell the direction of an ambulance siren?
The GFP gene, which has its origins in jellyfish, expresses proteins that fluoresce when illuminated with certain frequencies of light.
Richter's magnitude values were calculated using only certain frequencies measured by seismographs, and other seismologists later developed more accurate measures.
But using a borrowed transducer, Michael soon found that very low power would kill mosquito larvae at certain frequencies because of a biological quirk.
Consequently, an array of speakers can be programmed to emit certain frequencies at different moments and decibels so that they will mimic sound coming from a specific location.
The ear gives unequal weights to certain frequencies, making it particularly sensitive to sounds in the range of 1,000 to 6,000 hertz, scientists say.
The elements in devices like Dr. Nguyen's have so little mass that at certain frequencies air molecules can interfere with their vibration and reduce their selectivity.
