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