Stress Recovery Effects of High- and Low-Frequency Amplified Music on Heart Rate Variability

Table 1

Heart rate variability analysis.

	Auditory stimulus	Musical stimulus	Heart rate variability index (mean ± SD)
			HFnu (ratio)	LFnu (ratio)	LF/HF (ratio)	HR (bpm/min)
	WN	OM	0.40 ± 0.13	0.67 ± 0.11	2.01 ± 1.72	77.95 ± 8.99
		HFM	0.42 ± 0.12	0.60 ± 0.16	1.87 ± 1.41	78.51 ± 8.47
		LFM	0.47 ± 0.16	0.63 ± 0.18	1.91 ± 2.23	77.03 ± 9.12
	SN	OM	0.25 ± 0.11	0.50 ± 0.19	4.38 ± 3.27	79.17 ± 8.05
		HFM	0.27 ± 0.10	0.58 ± 0.15	4.67 ± 3.79	78.91 ± 9.27
		LFM	0.30 ± 0.13	0.58 ± 0.18	4.30 ± 2.80	79.62 ± 8.28
	MS	OM	0.46 ± 0.13	0.55 ± 0.15	1.65 ± 1.11	76.80 ± 9.34
		HFM	0.52 ± 0.14	0.53 ± 0.14	1.48 ± 1.66	78.61 ± 9.80
		LFM	0.51 ± 0.11	0.52 ± 0.16	1.33 ± 0.95	75.46 ± 8.97
GEE; value	Auditory stimulus		0.001	0.001	0.001	0.13
	Music stimulus		0.001	0.98	0.74	0.13
	Auditory stimulus × music stimulus		0.68	0.07	0.98	0.04
	Order effect		0.69	0.37	0.22	0.96

⁢; HFM: music with an amplified high-frequency component; HFnu: high-frequency normalized unit; HR: heart rate; LF/HF: low-/high-frequency ratio; LFM: music with an amplified low-frequency component; LFnu: low-frequency normalized unit; MS: musical stimulus; OM: original music; SD: standard deviation; SN: stress noise.