Frequency ranges of the human voice

Average range of frequencies for men, women, and children

The average man’s speaking voice, for example, typically has a fundamental frequency between 85 Hz and 155 Hz. A woman’s speech range is about 165 Hz to 255 Hz, and a child’s voice typically ranges from 250 Hz to 300 Hz and higher. 

Of course, each of us has a wider range of sounds that our vocal cords can produce, and if we choose to sing, that range can extend up to four octaves. To help you visualize that, a standard piano keyboard has 88 black and white keys, and covers a frequency range from 27.5 Hz to 4186 Hz, over seven musical octaves (“middle C” is at 261 Hz). One octave represents 12 tones, white and black keys included. 

We hear the frequency of speech or singing as the pitch, and a doubling of the fundamental frequency represents an octave. If you were singing a note at 100 Hz and then sang it at 200 Hz, you’d hear it as “twice as high.” If you sang a note at 180 Hz and then tried for a really low note, at 90 Hz, the latter would be an octave deeper.

But what’s surprising in all this is that the entire range of men’s and women’s voices remains between about 65 Hz for a male with a very deep bass voice to the highest note of a female coloratura soprano, just above 1,000 Hz, at 1,280 Hz. (A female high-pitched scream can go quite a bit higher, to around 3,000 Hz.)

Source: Audio Oddities: Frequency Ranges of Male, Female and Children's Voices

Chart showing the frequency charts for males, females, and children

According to these charts, the loudest frequencies for men are from about 125-750 Hz.

For women, it's about 180-1,800 Hz.

Women have a small peak around 4,000 Hz for normal speaking voices.

Source: FACTS ABOUT SPEECH INTELLIGIBILITY

Testosterone and Estrogen levels Affect the Whole Body and the Brain

Research articles showing how Testosterone and Estrogen (Estradiol) cause different brain chemistry/function between men and women.

Clinical research has demonstrated a significant sex difference in the occurrence of depressive disorders. Beginning at pubertal onset, women report a higher incidence of depression than men. Women are also vulnerable to the development of depressive disorders such as premenstrual dysphoric disorder, postpartum depression, and perimenopausal depression. These disorders are associated with reproductive stages involving changes in gonadal hormone levels. Specifically, female depression and female affective behaviors are influenced by estradiol levels. 
Estrogenic mediati... [Prog Neuropsychopharmacol Biol Psychiatry. 2014] - PubMed - NCBI

The literature suggests that while there are many similarities in brain structure, function, and neurotransmission in healthy men and women, there are important differences that distinguish the male from the female brain. 
Evolving knowledge of sex differences in bra... [Biol Psychiatry. 2007] - PubMed - NCBI

Of particular interest are sex differences that have been identified in the brain. Although the brains of men and women are highly similar, they show consistent differences that have important implications for each sex. That is, brain sex differences uniquely affect biochemical processes, may contribute to the susceptibility to specific diseases, and may influence specific behaviors. Such biological differences should never be used to justify discrimination or sexism. However, we believe that a thorough understanding of these differences can inform researchers and clinicians so that they can better address important issues. Two examples include how genetic sex can lead to differences between the sexes in the etiology and the progression of disease and how differences in neural development may result in differences in cognition and behavior.
The Genetics of Sex Differences in Brain and Behavior

"...sociologist J. Richard Urdy has found that females' responsiveness to encouragement of femininity is inversely related to their mothers' testosterone levels during the second trimester of pregnancy.

"...female rhesus money injected with androgens during the prenatal critical perioid later display stereotypic male sexual and nonsexual behavior.  They engage in higher frequencies of threat behavior, play initiation, rough-and-tumble play, and chasing play...a consistent relationship between hormones and behavior emerges that is not easy to dismiss by invoking different ad hoc criticisms of the individual findings.
Book: Biology at Work: Rethinking Sexual Equality

The incidence of psychopathy in the general population is generally considered to be 0·6-4% with a higher proportion of males to females. Brain imaging studies of psychopaths suggest a smaller and less active amygdala and prefrontal cortex. There also appear to be physiological derangements in psychopathy, including alterations/dysregulation in neurotransmitter homeostasis (dopamine and serotonin), altered endocrine responses (testosterone and cortisol)
Psychopathy: clinical features, developmen... [J Clin Pharm Ther. 2014] - PubMed - NCBI

The recognition memory tasks, novel object and novel object location, have been beneficial to neuroendocrine research concerning the effects of gonadal and adrenal hormones on cognitive function...Experiments conducted across a number of laboratories show that gonadal hormones, both estradiol and testosterone, promote memory while the adrenal hormone, corticosterone, impairs memory.
Department of Psychology, Hunter College of CUNY.
Recognition memory tasks in neuroendocrine r... [Behav Brain Res. 2014] - PubMed - NCBI

The gonadal steroids play an important role in altering the survival or death of neurons within the brain as well regulating the development of neuronal processes (such as the number and length of dendrites and dendritic spines, or the degree of axonal branching). In this regard, we can say that steroid hormones have organizational effects that produce sex differences in the connections and functions of the brain. Gonadal steroids also have activational effects; these activational effects are transient and are thought to coordinate behavior with either an internal event, such as ovulation, or an external event, such as the presence of a sexual partner.
Psychology Course
http://www.umich.edu/~psycours/531/becker.chapter3.htm

The specific impact of sex hormones on brain development and acoustic communication is known from animal models. Sex steroid hormones secreted during early development play an essential role in hemispheric organization and the functional lateralization of the brain, e.g. language. In animals, these hormones are well-known regulators of vocal motor behaviour.
Sex hormone influence on human infants' sound char... [Biol Lett. 2014] - PubMed - NCBI

Boys with higher levels of prenatal testosterone who were also exposed to higher levels of nicotine and alcohol during pregnancy exhibited increased hyperactivity-impulsivity during early childhood, but girls did not exhibit this same pattern. Thus, high prenatal testosterone exposure seems to increase risk for DBD symptoms particularly in males by increasing susceptibility to prenatal environmental stressors.
Prenatal testosterone increases sensiti... [Neurotoxicol Teratol. 2014] - PubMed - NCBI

Genistein is a phytoestrogen, particularly abundant in soybeans, that is able to bind estrogen receptors exerting both estrogenic and antiestrogenic activities. Genistein is largely present in the human diet even during pregnancy. Embryos and fetuses are therefore, commonly exposed to genistein during the development and after birth. In the present study, we used a murine model as a test end-point to investigate the effects of early exposure to genistein on adult male behavior and related neural circuits. Exposure of dams to genistein (100μg/g of body weight) daily during late pregnancy and early lactation, produced in male offspring, when adults, significant changes in anxiety behavior and statistically significant variations in the number of neuronal nitric-oxide synthase positive cells in the amygdala. In conclusions, these data indicate that early exposure to phytoestrogens may induce life-long effects on the differentiation of brain structures and behaviors.
Perinatal exposure to genistein affects the no... [Physiol Behav. 2014] - PubMed - NCBI

Cancer immunity and viruses

Excerpts from this article, written by a radio-oncologist
IS CANCER CAUSED BY VIRUS?

Under microscope, Rife observed conversion was due to accumulated toxins and waste products in the cells in different parts of body. He came to the conclusion that exposure to carcinogens slowly alters the constitution and makes body ready for cancer. BX viruses then grow within the body and invade the cells to cause cancer.

According to Dr. John Cairns of Harvard University School of Public Health, chemotherapy is curative only in 2% to 3% of all cancer patients although it is routinely given to more than 50% cancer patients in America.

Salmonella Incubation Period

With all of the recent intense media coverage about certain Peanut Butter products being tainted with Salmonella, I wanted to find out a little bit about Salmonella's incubation and treatments.

From a Cornell Press Release:

Once Salmonella has been ingested, the "incubation time" or period from ingestion until the first symptoms of illness occur ranges from 12 to 72 hours. The time to illness may vary depending on many things such as the host's overall fitness and age, the amount and serotype of Salmonella ingested (with some serotypes as few as 20 cells), and the presence of various "stress" factors such as whether the person is undernourished, etc.

Salmonella symptoms are similar to other food poisoning: diarrhea, cramps, vomiting, etc. According to the Mayo Clinic, there's no reliable treatment for Salmonella. Treatment involves antibiotics, fluid replacement, and avoiding milk products to alleviate abdominal pains. These treatments are usually for people with weakened immune systems and immuno-compromised people.

For healthy people, the symptoms "subside within several days to two weeks" without treatment.

Mayo Clinic - Salmonella Infection: Treatments and Drugs