How to Whistle Loudly - Loud Whistle Techniques

Fact about whistling
Whistling while you work may not win you many friends - but it could help you do your job better. A leading psychologist claims whistling or singing helps distract the mind from trying too hard and prevents mental overload. So, it won't be bad if you learn to whistle a bit and lighten your work stress.
A Whistled Language
The inhabitants of La Gomera, situated in the Canary islands, speak Silbo Gomero, a completely whistled language.
Learning to whistle loudly is not an esoteric skill, that can be mastered by only a few. The techniques are simple and can be easily mastered with practice and patience, by anybody. You can have a lot of fun in the process, of course. Loud whistles are a very effective way of grabbing anybody's attention. It is also an established, albeit raunchy form of appreciation.

For some, whistling is an art. There are people who give whistling performances and renditions to large audiences. They whistle songs and their own compositions. It is perhaps one of the most ancient signaling mechanisms used by men. Army men and guerrillas have elaborate whistling codes to warn about threats. Some people imitate the sounds made by birds through whistles. It is a very crazy, funny, and yet useful skill to master. There is even an 'International Whistlers Convention' held every year, where artists demonstrate their skills and talents.
Physics of Whistling
A whistle is made possible by the resonant cavity created in the mouth and the forceful blowing of air through a very small opening, that creates turbulence. The turbulence creates friction, thus leading to the vibration of the air column, in the mouth. This creates sounds of different frequencies. This is similar to something that happens in a flute, where different lengths of resonant cavities are created, which give you different tones of music.

A standing resonant cavity is created in the mouth, which can give you different tones. The pitch of the whistle is dependent on the size and shape of the resonant cavity. To increase the volume, that is to whistle loudly, one must increase the vibrating amplitude of the resonant cavity. This can be effectively done by modifying the shape of the mouth cavity and making the hole smaller in diameter, through which turbulence is created. That is, by forcing the air through a narrower hole.

There are two main types of techniques, one that uses fingers (wolf whistling) and one that just uses the mouth (fingerless mouth whistle). The former is more effective in creating a loud resonant sound.
Whistling Loud With Fingers
This technique uses fingers, placed in the mouth, to create another type of resonant cavity. This is the non-musical type and is blown in short small loud bursts generally, to express appreciation, call a cab, or call anyone to grab attention.

There are two prime techniques, depending on the finger combination. You could either use:
  • the index finger and thumb of one hand or
  • the index and middle fingers of both hands.
Choose whichever combination you want. Here is an illustrated explanation of both techniques.
Using Index Finger and Thumb
Step 1: Lightly press your index finger against the thumb, such that the fingertips are touching.
Step 2: Keeping them joined together, insert them into your mouth, till they touch the drawn back tongue. The placing of both fingers should be roughly halfway between the lip center and corners. The fingernails must be angled towards the tongue center and not towards the roof of the mouth. Also, they should make the lower lip cover the lower set of teeth, in a taut fashion.
Step 3: Now, position the tongue, such that its tip touches the base of your mouth, about one centimeter behind your lower teeth gums. Let the fingers push against the tongue, at its bottom.
Step 4: Now comes the finale. Inhale and blow air over your tongue, directing it towards the lower lip and the hole created between the fingers. The tongue, along with the lips will create a resonant cavity and you may hear your first loud whistle. Adjust and experiment a bit, with the position of the fingers and the angle created by the tongue. With a bit of practice, you should get it.
Using Both Index and Middle Fingers
Step 1: Create an 'A shape', using the index and middle fingers, as shown in the illustration below.
Step 2: Next, draw in the upper and lower lips, such that they cover both sets of teeth.
Step 3: Push your tongue, back into the mouth, about a centimeter behind the lower teeth gum line. Insert your fingers into the mouth, such that fingertips touch the tongue bottom.
Step 4: Inhale and blow air towards the perforation created between the fingers and you should hear your first loud whistle. Keep practicing to get the angle right.
There is a third way of doing it too, using just the index fingers or pinkies of both hands, with the same whistling technique in principle. Some people even achieve the same effect with a single finger. It takes time to get these techniques right. You may have to experiment and modify the length of fingers inserted, the applied pressure, and other things. Persistence again, is the key.
Whistling Without Fingers
This is the easiest technique to master, according to my personal experience. It only uses the lips, the mouth muscles, and the tongue, to create the whistling sound. Here's how it's done.

Get your lips into position, in just the way you get them to pronounce the letter 'O', but close the lips more, to create a smaller hole between your lips.
Let your tongue touch the front roof of the mouth, where you have those two 'U' shaped indentations (palate or alveolar ridge), that create a small reverse 'U' shaped gap in between.
Then, breathe deeply and just blow through this passage, created between the tongue and the lips.

If you follow these instructions to the letter, you will hear a resonant sound, which is the whistle. It is most likely that you will not get it right away but practice will get you there. Making it more loud and resonant, will require time and effort.

It takes some time and adjustment to get your sweet spot and your sound. Personally, I enjoy my whistling sessions. It's the most natural music you could create. The generated sound can be loud, depending on the level of resonance that you create. There are many variations. Some people whistle through teeth, some inhale air into the mouth, instead of exhaling, and some, as we have seen, use fingers.