diff --git a/src/index.ts b/src/index.ts
index cb3f5f2..9217199 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,11 +1,4 @@
-/**
- * Replaces all standard vowels (a, e, i, o, u, case-insensitive) in the input string with the specified mask character.
- * @param input The string to process.
- * @param mask The character to replace vowels with.
- * @returns The processed string with vowels replaced.
- * @throws {Error} If mask is not a non-empty string.
- */
-export function muteVowels(input: string, mask: string): string {
+export function muteVowels(input: string, mask: string = '*'): string {
   if (typeof input !== 'string') {
     throw new Error('Input must be a string');
   }