A person recently asked me what I meant by the term business system.. I thought others might like to know a definition that works for me. A system is a procedure, process, method, or course of action designed to achieve a specific result.
The voiced speech of a typical adult male will have a fundamental frequency from 85 to 180 Hz, and that of a typical adult female from 165 to 255 Hz. Thus, the fundamental frequency of most speech falls below the bottom of the voice frequency band as defined above.
Most Baritone/bass men can sing down to E2 which is 82 Hz, and a great many basses can sing two octaves below middle C, which is 65 Hz. Most men with low speaking voices are producing fundmentals in the 100 Hz range, and the booming professionals with radio voices can can easily speak in the 60-80 Hz range.