A space has all hard surfaces including architecture and furnishings. The audio programming produced from the distributed sound system has become unintelligible. Which of the following will NOT mitiga

Tapestries add absorptive surface area, converting acoustic energy to heat and shortening reverberation time, which directly improves intelligibility.

More speakers at lower individual output levels keep direct sound levels adequate while feeding less energy into the reverberant field, improving the direct-to-reverberant ratio.

Increasing volume on existing speakers pumps more acoustic energy into the room, elevating the reverberant field and reducing the direct-to-reverberant ratio. This degrades speech intelligibility further instead of mitigating it, making C the one action that does NOT help.

Reducing speaker-to-listener distance increases the direct sound level relative to the reverberant background, improving signal-to-noise ratio and intelligibility.