Use the sliders, type the tone frequency in Hertz or select a preset and press Play
This portal provides a free Binaural Tone Generator
"Binaural beats, or binaural tones, are auditory processing artifacts, or apparent sounds, caused by specific physical stimuli. This effect was discovered in 1839 by Heinrich Wilhelm Dove and earned greater public awareness in the late 20th century based on claims coming from the alternative medicine community that binaural beats could help induce relaxation, meditation, creativity and other desirable mental states. The effect on the brainwaves depends on the difference in frequencies of each tone: for example, if 300 Hz was played in one ear and 310 in the other, then the binaural beat would have a frequency of 10 Hz."