First, check what you're scanning. The maximum scan size for the flatbed is 8.5 x 11.7 inches. If your document is larger or isn't lying flat, it could cause issues.
Next, ensure the operating environment is correct. The scanner is a color flatbed CIS type. It should be used in temperatures between 50° and 95°F (10° to 35°C). Extreme temperatures or humidity outside the 20% to 80% range (with no condensation) can affect mechanical parts.
If the sound continues with a standard-sized document, it may indicate a hardware problem covered under the 2-year limited warranty, provided you've registered the product.