From Otto Jespersen's Growth and Structure of the English Language, first published in 1938 -- “... there is one expression that continually comes to my mind whenever I think of the English language and compare it with others: it seems to me positively and expressly masculine, it is the language of a grown-up man and has very little childish or feminine about it. A great many things go together to produce and to confirm that impression, things phonetical, grammatical, and lexical, words and turns that are found, and words and turns that are not found, in the language.”
Of a passage in Hawaiian, Jespersen notes that “no single word ends in a consonant, and a group of two or more consonants is never found. Can any one be in doubt that even if such a language sound pleasantly and be full of music and harmony the total impression is childlike and effeminate? You do not expect much vigour or energy in a people speaking such a language..” The history of Polynesian warfare and maritime exploration count for little in the face of this damning excess of vowels.
The English don't overdo their consonants -- Jespersen notes that in the first ten stanzas of Tennyson's poem “Locksley Hall,” there are thirty-three words ending in two consonants and two words ending in three consonants: “Thus we may perhaps characterize English, phonetically speaking, as possessing male energy, but not brutal force.”
It's easy to mock these particular examples, and the chauvinistic assumptions they're wrapped up in -- but how much do we still subconsciously believe this kind of thing? Not knowing what the initials stood for, would you rather be taken into custody by the A.I.O.U or by the V.V.V.K? If you wrote a story with a masculine character and an effeminate character, which of them would you be more likely to give a name ending in, or beginning with, three consonants? Does naming an intergalactic warlord Zdragorn reinforce prejudices about people who speak language full of consonant clusters?
Perhaps more importantly, has anyone actually done an experiment to prove or disprove whether the ratio of vowels to consonants in your daily speech alters your levels of various sex hormones? All I'm saying is that it would be worth trying to do the experiment. The orthodoxy in linguistics is Saussure's postulate that “the sign is arbitrary” – hence no vowel or consonant can have any intrinsic meaning. Phonosemantics researcher Margaret Magnus has argued that this slogan “the sign is arbitrary” is “posted near the beginning of every introductory linguistics book as a sort of road block. 'Do not engage in a particular form of research.' And it works!”
But what if Saussure's position is too extreme? A laugh, a scream, a syllable chanted in meditation... each has some kind of meaning, and by uttering them we can alter our body chemistry... is the same never true of a phoneme?