Mosquito ringtones emit high-frequency tones that are inaudible by adults but can be heard by teenagers. It is very normal for people to lose their hearing as they age. The loss of hearing is gradual in most people, while other may experience more severe hearing loss. The high-frequency tones (or mosquito ringtones) are those above 17kHz. Most people over the age of 30 will not be able to hear them. Below are file downloads in MP3, WAV for windows based phones, OGG (Ogg Vorbis audio format), and M4R (iPhone file format).