Speech intelligibility

The ear / brain processor can fill in a substantial amount of missing information in music, but requires more detailed information for understanding speech. The speech power is delivered in the vowels (a, e, i, o, u and sometimes y)which are predominantly in the frequency range of 250Hz to 500Hz. The speech intelligibility is delivered in the consonants(b, c, d, f, g, h, j, k, l, m, n, p, q, r, s, t, v, w) which requires information in the 2,000Hz to 4,000Hz frequency range. People who suffer from noise induced hearing loss typically have a 4,000Hz notch, which causes severe degradation of speech intelligibility. Most telephones have a limited usable bandwidth of less than 4,000Hz, and you may have noticed that it can make it difficult to hear the difference between the letters b, d, t, and v, and also between f and s, on the phone.

Vowels have more sound energy available as well, the consonants that give us the detail and information in speech are quite low in level. Just think of how loud you could shout the letter "O" versus the letter "T". It is ironic that the most critical aspect of speech is also the lowest in energy, but then our ear has a hearing mechanism that is finely tuned to 2kHz to make it very sensitive to sounds in that range.

The next time you hear somebody bragging about how great their Kenwood, Icom, or Yaesu Ham rig is listen carefully to the speech intelligibility and the ability to differentiate between the letter s and the letter f. Most Ham radios have an upper frequency response limitation of 3500 Hertz
Or less.

This is what a 4000 hertz top end sounds like.

 

Being able to pass the audio frequency through the transmitter is only a third of the battle. Finding a decent microphone able to Faithfully reproduce every syllable of the English language is the other third of the battle.
Then carefully enunciating every word is the other third of the battle.

 

Precisely why I use a capacitor as a high pass filter to cut off the bottom end.
By the way the hissing sound in the letter s uses the same 5300 hertz frequency regardless of whether you are a baritone or a soprano.

When it comes to speech, vowels are low-frequency sounds – they lend the voice its richness, sexiness, and identity. Consonants, in contrast, are generally higher frequency sounds – they provide clarity and diction to speech. For example, the difference between the letter “S” – which has a hissing sound – and “F” – which lacks that hissing sound – is roughly 6,000 Hz in men and 8,000 Hz in women. While both sounds are formed the same way, air squeezing between the tip of tongue and the roof of the mouth, if you can hear the hiss, the letter is an “S.” If you can’t, it’s an “F.”
Here is the letter S as spoken by a 2 year old girl and a 500 pound man. 5305 hertz. So for someone to say audio Beyond 3000 hertz is useless is actually quite ridiculous when it comes to differentiating between the letter S and the letter F.

 

Prime example of inefficient bandwidth usage.
He has to compensate with massive amounts of power for the huge bandwidth

 

Unfortunately that's not how John sounds in real life. There's lots of distortion.
If you have enough money he will be more than happy to build you a station from scratch.
http://www.motormouthmaul.com/
He will even fly to your house and help you install the antenna system and install everything for the right amount of money