Music for Reducing Anxiety Before Surgery

The goal of this clinical trial is to learn whether listening to self-selected music through headphones for 30 minutes before surgery lowers state anxiety in adults waiting for elective surgery. The main question it aims to answer is: Do adults (ASA physical status I-II) who listen to music for 30 minutes in the preoperative waiting area have lower state anxiety scores (STAI-Y1) than adults who receive usual care? Researchers will compare a music group with a usual-care group to see whether state anxiety, blood pressure, heart rate, and respiratory rate differ after 30 minutes. Participants will: * Complete the Vietnamese version of the STAI-Y1 questionnaire and have vital signs measured before the intervention * Either listen to music they choose from a researcher-prepared playlist through over-ear headphones for 30 minutes, or wait in the preoperative waiting area under usual care for 30 minutes * Complete the STAI-Y1 again and have vital signs measured 30 minutes after the start of the intervention

Inclusion Criteria: * Aged 18 years or older * Scheduled for elective surgery at Thu Duc General Hospital * American Society of Anesthesiologists (ASA) physical status I or II * Alert and well oriented * Able to read, understand, and communicate in Vietnamese * Expected waiting time in the preoperative area of at least 40 minutes * Agrees to participate and provides written informed consent Exclusion Criteria: * Hearing impairment or use of a hearing aid * Psychiatric disorder, or currently treated with sedatives or antidepressants * Skin lesions on the head or ear region, or acute ear infection * Cognitive impairment, altered consciousness, or inability to complete the questionnaire independently * Received premedication or sedatives before the 30-minute assessment (T1)