A generalized cumulative noise exposure metric for community response analysis.

In community noise studies, there is often a desire to understand how the annoyance response to multiple noise events aggregates over a long period of time. Many cumulative response metrics, such as day-night level (DNL), are based on the idea that humans respond, on average, to the sum of frequency-weighted acoustic energy over time. This paper introduces a generalization of DNL that includes a parameter, b, that ranges between zero and one.

Sound quality metric indicators of rotorcraft noise annoyance using multilevel analysis.

It is hypothesized that sound quality metrics, particularly loudness, sharpness, tonality, impulsiveness, fluctuation strength, and roughness, could all be possible indicators of the reported annoyance to helicopter noise. To test this hypothesis, a psychoacoustic test was conducted in which subjects rated their annoyance levels to synthesized helicopter sounds. After controlling for loudness, a previous analysis using linear regression identified sharpness and tonality as important factors in predicting annoyance, followed by fluctuation strength.