Yes, it is possible to produce a sound similar to a whistle without using your mouth. One way to achieve this is by using an object that can generate sound when air passes through it. Here are a few methods you can try:
Whistle with your fingers: Place your fingers (usually the index and middle fingers) tightly together and position them against your lips. Blow air through the small opening created between your fingers and adjust the angle and position until you produce a whistling sound.
Whistle with a blade of grass: Find a long, thin blade of grass and hold it between your thumbs or index fingers. Position the blade of grass near your lips, leaving a small gap for the air to pass through. Blow gently across the blade of grass, adjusting the tightness and angle until you achieve a whistling sound.
Whistle with a paper or plastic whistle: If you have a small whistle made of paper or plastic, you can use it to produce a whistle sound without involving your mouth. Simply blow air through the whistle, and it will generate the desired sound.
Whistle with a musical instrument: Many musical instruments, such as the recorder or the tin whistle, are designed to produce whistle-like sounds. By blowing air into the instrument and using fingerings or specific techniques, you can create various whistle-like tones and melodies.
These methods allow you to create a whistle-like sound without using your mouth directly. Experimenting with different objects and techniques can help you achieve different pitches and tones.