Table 2.
Detection of sound
source prevalence across land use areas in the Greater Accra Metropolitan Area*.
| Road-transport (%) | Animals and insects (%) | Outdoor music (%) | Human speech (%) | Nature (%) | Aircraft (within flightpath)** | Aircraft (outside flight path)** | Other (%) | |
|---|---|---|---|---|---|---|---|---|
| Rotating sites | ||||||||
| Greater Accra Metropolitan Area | 64 | 39 | 10 | 23 | 4 | 29 | 14 | 39 |
| Accra Metropolitan Area | 78 | 24 | 13 | 29 | 2 | 29 | 15 | 35 |
| Land use*** | ||||||||
| Peri-urban background | 40 | 65 | 4 | 8 | 9 | – | – | 41 |
| Medium/ low-density residential | 64 | 43 | 10 | 22 | 3 | – | – | 40 |
| High-density residential | 71 | 30 | 15 | 33 | 2 | – | – | 40 |
| Commercial, business, industrial | 85 | 16 | 9 | 28 | 1 | – | – | 31 |
| Fixed sites**** | 82 | 16 | 16 | 29 | 1 | – | – | 32 |
Data are expressed as the percentage (%) of site-time present.
*The top three sound classes based on modelled probability of presence were retained for each 10-s audio clip.
**Within/outside of 1 km of take-off/descent flight path for Kotoka airport (n = 7 rotating and n = 1 fixed site near flight path).
***Medium/low-density residential are typically formal residential areas; high-density residential are typically informal residential areas and could be classified as shantytowns or slums; peri-urban background are the least built-up areas and typically have an abundance of forest, grass land, shrubs, barren land, and/or water; commercial, business and industrial areas are places which are dominated by commercial, business, industrial, and/or government activities (see full criteria in S8).
*** 9 fixed sites had 3 CBI areas along major motorways, 2 sites in high-density residential neighborhoods, 3 sites in medium/low-density residential areas and one at a peri-urban location.