Heart rate variability (HRV) is known to reflect the balance of autonomic nervous system. Anxiousness, which tend to result from the deficient action of parasympathetic nervous system, likely to show low HRV. This study is to investigate the relationship between the surgery-related anxiety and the HRV which is known to reflect the balance of autonomic nervous system. Furthermore, this study also focuses on HRV's role as a predictor for aggressive emergence behavior, which might also be considered as partially related to imbalance of autonomic nervous system.

Inclusion Criteria:

1. 20-60 years old male, ASA 1-2
2. scheduled for elective closed reduction for nasal bone fracture

Exclusion Criteria:

1. Patients having hearing difficulties, Foreigner, taking any CNS related medication, history of any adverse drug reaction, Glasgow coma scale < 15
2. patients with severe cardiopulmonary dysfunction
3. patients taking any neurologic medication (anti-depressant, anti-convulsant, etc)
4. patients taking any cardiovascular medication
5. patients taking medications affecting the autonomic nervous system (a-blocker, b-blocker, etc)
6. patients refusal

20-60 years old male, ASA 1-2, scheduled for elective closed reduction for nasal bone fracture.