Soundscape　plays　a　positive,　health-related　role　in　urban　forests,　and　there　is　a　competitive　allocation　of　cognitive　resources　between　soundscapes　and　lightscapes.　This　study　aimed　to　explore　the　relationship　between　perceived　loudness　sensitivity　and　brightness　in　urban　forests　through　eye　opening　and　closure.　Questionnaires　and　measuring　equipment　were　used　to　gather　soundscape　and　lightscape　information　at　44　observation　sites　in　urban　forested　areas.　Diurnal　variations,　Pearson＇s　correlations,　and　formula　derivations　were　then　used　to　analyze　the　relationship　between　perception　sensitivity　and　how　perceived　loudness　sensitivity　was　influenced　by　lightscape.　Our　results　suggested　that　soundscape　variation　plays　a　role　in　audio-visual　perception　in　urban　forests.　Our　findings　also　showed　a　gap　in　perception　sensitivity　between　loudness　and　brightness,　which　conducted　two　opposite　conditions　bounded　by　1.24　dBA.　Furthermore,　we　found　that　the　effect　of　brightness　on　perceived　loudness　sensitivity　was　limited　if　variations　of　brightness　were　sequential　and　weak.　This　can　facilitate　the　understanding　of　individual　perception　to　soundscape　and　lightscape　in　urban　forests　when　proposing　suitable　design　plans.