Sound annoyance

Sound annoyance is 'a feeling of displeasure associated with any agent or condition that is believed to affect adversely an individual or a group'. Sound annoyance is 'a feeling of displeasure associated with any agent or condition that is believed to affect adversely an individual or a group'. Annoyance implies a negative factor on an individual's well-being and comfort. Its effects may include physiological responses, central nervous system reactions, and biochemical changes. Physiological reactions to sound annoyance include increased heart rate and increased blood pressure which, among others, may lead to hypertension. Hearing impairment, such as increased hearing threshold, and tinnitus are considered as another possible consequence of sound annoyance. EEG and Magnetoencephalography studies show an increased activity in several parts of the Central Nervous System. Biochemical changes due to sound annoyance include increased secretion of epinephrine, which is related to the 'fight'-reaction (See fight-or-flight response) and increased adrenal cortical activity (see adrenal cortex), which is related to intense and/or stressful events. Epidemological investigations have shown that the negative effects of sound annoyance include 'a feeling of resentment, displeasure, dissatisfaction, discomfort or offence when noise interferes with someones thoughts, feelings or actual activities'. Besides that, unwanted sounds can mask the positive indicators of safety. These factors may diminish well-being of people that suffer from sound annoyance. Other factors that correlate with sound annoyance are increased absence form work, sleep disturbance, and interference with performing cognitive tasks like paying attention at school. For a more detailed article about health effects: health effects from noise. Historically, nuisance sound has been measured using A-weighted sound pressure level metrics such as LA,Smax which indicates the maximum sound pressure level with one-second time integration, LDN, a 24-hour average of daytime and weighted nighttime sound level, or other long term time-averages. Measurement is made using a sound level meter with appropriate statistical averaging and corrections to predict the level of sound presented to a human listener. Psychoacoustic analysis reveals that sound pressure level is a less than ideal predictor of human reception of noise, so efforts have been made since the 1960s to apply loudness metrics instead, which can incorporate other factors such as spectral and temporal auditory masking and level-dependent frequency weighting to more accurately track human reception. Integration of individual sounds into an auditory or dose estimate has traditionally followed an extension of Stevens's power law which applies simple power or energy summation such that a sound lasting twice as long is considered of equal impact as one 3 dB higher in amplitude. More recent work such as Moore and Glasberg on time-varying loudness and Nordtest NT ACOU 112 has examined a more detailed understanding of other factors such as onset rate and masking. The European Union (EU) set up European guidelines in respect to noise pollution. For nighttime, it is advised to not exceed the 40 dB Lnight threshold outside the residence. An interim threshold of 55 dB Lnight is set as an upper bound, because above this limit, (sleeping) disorders are more prevalent. However, about 20% of people living in or near urban areas suffer from sounds at night that exceed even the interim threshold.