Hypersonic effect Hypersonic effect The hypersonic effect is a term coined to describe a phenomenon reported in a controversial scientific study by Tsutomu Oohashi et al., which claims that, although humans cannot consciously hear ultrasound (sounds at frequencies above approximately 20 kHz), the presence or absence of those frequencies has a measurable effect on their physiological and psychological reactions. Numerous other studies have contradicted the portion of the results relating to the subjective reaction to high-frequency audio, finding that people who have "good ears" listening to Super Audio CDs and high resolution DVD-Audio recordings on high fidelity systems capable of reproducing sounds
10-meter band repeater channels, "odd-splits" (offsets differing from 100 kHz) and non-standard frequencies are not uncommon. Since 10 meters can frequently open up to propagate globally, most 10-meter repeaters use a CTCSS sub-audible access tone. 16 kHz wide signals with 5 kHz deviation is normal in this band. 8 kHz narrow signals with 2.5 kHz deviation can also be found. 29.300 MHz is a common frequency to find JA hams on. British hams commonly use the 29.400 to 29.500 MHz band for FM as well with 29.400, 29.450, and 29.500 MHz being common. USA hams can be found on FM anywhere above