Research presents nuanced results. A 2022 Nature Scientific Reports study found that white noise at 45 dB in a private office setting improved sustained attention, accuracy, and processing speed compared to office ambient noise. However, this effect applies to non-speech audio in controlled levels — music with lyrics activates the language processing network and can generate an ISE-like effect for verbal cognitive tasks. The weight of evidence supports that genuine quiet (≤35 dB, no intelligible speech) produces the most consistent improvements in complex cognitive performance across task types.