Ireland's State of the Environment Report 2024

59 Chapter 3: Environmental Noise Environmental Noise 1. Introduction 1 www.nuheara.com/usa/news/human-hearing-frequency-range/ (Accessed 26 September 2024). Environmental noise is unwanted or harmful outdoor sound arising from all areas of human activity. Although noise is a product of many human activities, including neighbourhood, industrial, commercial and entertainment activities, the most widespread sources of noise pollution and exposure in Ireland are various forms of transport. Reducing noise pollution is an ambition of the European Union (EU) Zero Pollution Action Plan (EC, 2021) and the Environmental Noise Directive (END) (2002/49/EC). Environmental noise has become a significant environmental health concern for European citizens and policymakers (EC, 2023), although in Ireland noise is often regarded as the forgotten pollutant (King and Murphy, 2016). The data from a recent noise mapping exercise in Ireland indicate that noise exposure from transport sources requires further investigation and follow-up action through local authority noise action plans, as over 1 million people are exposed to noise levels above the reporting thresholds set in the END. The human ear hears sound pressures over a wide range of frequencies. Measurements in decibels (dB) correspond to the way our ears interpret sound pressures and are given on a logarithmic scale (Figure 3.1). Figure 3.1  Human auditory range 0 dB 10 dB 20 dB 30 dB 40 dB 50 dB 60 dB 70 dB 80 dB 90 dB 100 dB 110 dB 120 dB 130 dB 140 dB Breathing Whispers Rainfall Car/traffic Hair dryer Trombone Jet engine Rustling leaves Fridge Conversation Trucks Helicopter Siren Fireworks Source: Adapted from Nuheara 1 The EU’s END mandatory noise level reporting thresholds are 55 dB L den and 50 dB L night : ■ L den is the day-evening-night long-term average noise indicator. It is ‘weighted’ to account for extra annoyance in the evening and during night-time periods. ■ L night is the night-time long-term average noise indicator and is used in the assessment of sleep disturbance. These indicators are based on year-long averages for the day-time (07:00-19:00), evening (19:00-23:00) and night-time (23:00-07:00) periods. Under EU legislation, Ireland must produce strategic noise maps every 5 years. The fourth round of noise mapping is the most recent undertaken (round 4). The maps cover major roads, major railways, one major airport (Dublin Airport) and the cities of Dublin, Cork and Limerick (i.e. agglomerations of more than 100,000 inhabitants).