Mosquito sound Sounds at frequency between 17.4 kHz and 20kHz. With the use of our app you can play sounds even with frequency between 9kHz and 22kHz (sounds above 20kHz are called Ultrasounds). How can you use this application? * Test your audio devices * Check if your audio devices (e.g. headphones, speakers, home theater) can play sounds at certain frequencies. * Check what sound frequencies you can hear * A lot of people over 50 years old lose their ability to hear high frequencies (it is called Presbycusis, age-related hearing loss). You can also try to use Mosquito sound as anti adult ringtone (a ring tone that only young people can hear and most adults can't). * Dog whistle * Try to train your dog with high frequency sounds (e.g above 20kHz), that can be heard by dogs, but are inaudible for most of humans. Remember Turn your volume to max while playing sound. Please also take into account that some built-in phone speakers are not able to produce all sound frequencies in range of 9kHz to 22kHz.