Which one has the more dangerous health effect...ultrasound or infrasound.? and why......
Depends how loud they are
can you explain more .what you mean.....
Frequencies within each band are also important. Cool tidbit: 18Hz is the resonant frequency of the eye and cause hallucinations
http://www.hpa.org.uk/webc/hpawebfile/hpaweb_c/1265028759369, here is a good read on the subject.
The dB of the sound is also important like Khashishi suggests. Try to reformulate your question and what specifically you want to compare between the two, all sounds have human health effects.
As, I know both are dangerous for health. But yeah! this is true that the frequencies matter.
But these are some of the only way in various diseases to detect what is going on and by which diseases you are suffering.
You need to furnish the mainstream research published in an acceptable journal that backs this up.
Separate names with a comma.