One instrument that can produce sounds similar to rainfall, wave sounds, wind sounds, and bird sounds is a rain stick. A rain stick is a cylindrical tube filled with small pebbles or beans, with small pins or thorns embedded along the inside surface. When the instrument is tilted, the pebbles or beans cascade down through the pins, creating a sound reminiscent of falling rain.
Rain sticks can be easily purchased at affordable prices from various musical instrument stores or online retailers. They come in different sizes and materials, so you can choose one that fits your preferences and budget. By controlling the angle and speed of the instrument's rotation, you can adjust the intensity and duration of the rain-like sound.
While a rain stick can produce soothing rainfall sounds, it may not be able to precisely mimic wave sounds, wind sounds, or bird sounds. For those specific sounds, you may need additional instruments or sound effects devices. However, if you are looking for a versatile and budget-friendly option to create a calming and atmospheric effect, a rain stick can be a great choice.