432 Hz.

1. Music effect: The pitch of 432 Hz is considered the most suitable for human hearing and can produce more natural and harmonious music effects. In comparison, the pitch of 528 Hz appears sharper and higher.

2. Health benefits: Some studies have shown that the frequency of 432 Hz can promote the circulation of qi and blood in the human body, relax the body and mind, relieve stress, and is beneficial to human health. The frequency of 528 Hz is slightly inferior to 432 Hz in these aspects.