The PRO 15 filter is suitable for unplugged musicians or singers, woodwind, brass, and orchestra musicians. From low frequencies to 2K instrument base frequencies, PRO 15 offers the world's flattest attenuation at 12dB. Then, starting at 12dB at 2KHz and continuing to 17dB at 8KHz, PRO 15 provides a progressing attenuation to protect your hearing from the loud high frequencies of strings and brass instruments.
The "occlusion effect" is the feeling you get when you plug up your ear canals and your voice echoes & rumbles inside your head.
The ACS PRO filter has an exclusive two-way conduction design that vents this blocked sound outward, virtually eliminating the occlusion effect. As a result, it enables you to hear your voice as close to your natural self as possible, eliminating any singing or communication obstacles while wearing earplugs. And because of the bi-directional conduction, the airtightness of the ear canal is also significantly reduced.
Why is this bi-directional conductivity essential for music earplugs? Usually, wearing earplugs is not to hear too much noise. When working in a noisy environment, you want to minimize communication with others. But the vast majority of music is written and performed with partners and usually involves singing. The ACS PRO filter allows you to hear your natural voice when you speak and sing—enabling you to communicate easily with other musicians and capture your singing pitch.
The chart below shows the attenuation curve of the PRO 15. The following chart shows the safe-listening-time of different PRO model filters under other ambient sound pressures. If the PRO 15 doesn't give you enough safe listening time at your ambient sound pressure, you should switch to a filter with higher attenuation, such as the PRO 17 or PRO 20.