a little help please?

Question

1) What is the lowset sound a human can here in hertz?
2)What do we call sound lower than it?
3)Can anything elses hear it?
4)what is the highest sound a human can here?
5)what do we call sounds higher than this?

Your help will be greatly appreciated thank you

Answer 1

1) 20 hertz - http://www.sciencebuddies.org/mentoring/project_ideas/HumBeh_p007.shtml
2) Infrasound - http://www.philtulga.com/MSSActivities.html
3)Dogs, elephants - http://skeptico.blogs.com/skeptico/2005/02/_a_friend_sent_.html
4)20,000 hertz - http://hypertextbook.com/facts/2003/ChrisDAmbrose.shtml
5) Ultrasound - http://www.ratbehavior.org/rathearing.htm

Answer 2

Humans can generally hear sounds with frequencies between 20 Hz and 20 kHz (the audio range) although this range varies significantly with age, occupational hearing damage, and gender; the majority of people can no longer hear 20,000 Hz by the time they are teenagers, and progressively lose the ability to hear higher frequencies as they get older. Most human speech communication takes place between 200 and 8,000 Hz and the human ear is most sensitive to frequencies around 1000-3,500 Hz. Sound above the hearing range is known as ultrasound, and that below the hearing range as infrasound.

Sounds in the range 20-100kHz are commonly used for communication and navigation by bats, dolphins, and some other species. Much higher frequencies, in the range 1-20 MHz, are used for medical ultrasound. Such sounds are produced by ultrasonic transducers.

Sources of infrasound in nature include volcanoes, avalanches, earthquakes and meteorites. The eruption of the Fuego volcano in Guatamala produced infrasonic sound in excess of 120 decibels in the range below 10Hz. Measurements on Mt Erebus, an active volcano in Antarctica, found very strong ultrasonic sounds while the audible sounds were unremarkable. Sound monitors on the Sakurajima volcano of Japan measured sharp signals just before an eruption. Ocean storms and waves generate a lot of infrasound. Early studies of infrasound of hurricanes offer some hope of deciphering the infrasound signature of an approaching hurricane.

Monitoring of infrasound seems to be one of the best ways for detecting atmospheric nuclear tests. As of 2004 there were 24 such monitoring stations out of a projected total of 60. While no nuclear tests have been detected, in 2003 10 stations in the U.S. and Canada monitored the explosion of the space shuttle Columbia. A station in Fairbanks, Alaska detected the explosion of dynamite five miles from the detector.

Infrasound detectors are used in Teton Pass, Wyoming to detect the frequent avalanches and send warning signals.

A number of animals produce and use sounds in the infrasonic range. The rumbling vocalizations of elephants were measured to have frequencies as low as 14 Hz which were detectable at a range of 10 km. Observations of elephant behavior suggests that they responded to the waves through the ground before they heard them in the air - plausible since the waves would travel faster in the solid material. Whales and rhinos produce some very low frequency sounds. The flightless cassowary birds of Papua New Guinea and Australia emit low frequency calls around 23 Hz.

Answer 3

A normal human can hear between 20 Hz and 20,000 Hz. That is quite a range. 20 Hz is a very low pitch sound or very deep tones. 20,000 Hz is a high pitch sound. Besides hearing low frequencies, you can often feel them. An example of that is when you can feel the bass from a loudspeaker.

When humans get older, they have trouble hearing the high pitched sounds and their detection range diminishes.
the source i am giving has a lot of info and charts