diff --git a/esphome/energymonitor.yaml b/esphome/energymonitor.yaml
index 22a1197..5e3fe9b 100644
--- a/esphome/energymonitor.yaml
+++ b/esphome/energymonitor.yaml
@@ -2,6 +2,7 @@ substitutions:
   device_description: "M5Stack Core dashboard for Home Assistant energy and internet usage, SCD30 room climate, analog/digital clock and WireGuard"
   name: "energymonitor"
   friendly_name: "Energy Monitor"
+  co2_beep_gain: "1%"
 
 esphome:
   comment: ${device_description}
@@ -101,6 +102,16 @@ output:
   - platform: gpio
     pin: GPIO32
     id: display_backlight_output
+  # The original M5Stack Core's speaker amplifier is connected to GPIO25.
+  - platform: ledc
+    pin: GPIO25
+    id: speaker_output
+    frequency: 880Hz
+
+rtttl:
+  id: co2_tones
+  output: speaker_output
+  gain: ${co2_beep_gain}
 
 light:
   - platform: binary
@@ -180,6 +191,10 @@ globals:
     type: int
     restore_value: true
     initial_value: '0'
+  - id: co2_alert_level
+    type: int
+    restore_value: false
+    initial_value: '-1'
   - id: climate_graph_view
     type: bool
     restore_value: true
@@ -233,6 +248,19 @@ sensor:
       name: "CO2"
       filters:
         - timeout: 30s
+      on_value:
+        then:
+          - lambda: |-
+              if (!std::isfinite(x)) return;
+              const int level = x > 1600.0f ? 2 : x > 1200.0f ? 1 : 0;
+              const int previous_level = id(co2_alert_level);
+              id(co2_alert_level) = level;
+              // Establish a silent baseline at startup; only upward crossings beep.
+              if (previous_level < 0 || level <= previous_level) return;
+              id(co2_tones).stop();
+              id(co2_tones).play(level == 2
+                  ? "co2high:d=16,o=5,b=150:a,p,a"
+                  : "co2warn:d=16,o=5,b=150:a");
     temperature:
       id: scd30_temperature
       name: "Temperature"
@@ -969,7 +997,7 @@ display:
           it.print(80, 140, id(font_small), temperature_color, TextAlign::TOP_CENTER, "Temperatur");
           it.printf(80, 164, id(font_title), temperature_color, TextAlign::TOP_CENTER,
                     temperature_valid ? "%.1f °C" : "-- °C", id(scd30_temperature).state);
-          it.print(240, 140, id(font_small), humidity_color, TextAlign::TOP_CENTER, "Feuchte");
+          it.print(240, 140, id(font_small), humidity_color, TextAlign::TOP_CENTER, "Feuchtigkeit");
           it.printf(240, 164, id(font_title), humidity_color, TextAlign::TOP_CENTER,
                     humidity_valid ? "%.1f %%" : "-- %%", id(scd30_humidity).state);
           if (!co2_valid && !temperature_valid && !humidity_valid) {
@@ -978,18 +1006,23 @@ display:
           }
         } else {
           draw_page_title("Raumklima · 1 h");
-          const int left = 28, right = 308;
+          const int left = 28, right = 308, top = 40, bottom = 142;
           const int count = id(climate_history_count);
-          const char *labels[] = {"CO2", "Temperatur", "Feuchte"};
+          const char *labels[] = {"CO2", "Temperatur", "Feuchtigkeit"};
           const char *units[] = {"ppm", "°C", "%"};
           const Color colors[] = {co2_color, temperature_color, humidity_color};
           const std::array<float, 361> *histories[] = {
               &id(climate_co2_history), &id(climate_temperature_history), &id(climate_humidity_history)};
           const float scale_steps[] = {100.0f, 1.0f, 5.0f};
           const float minimum_ranges[] = {200.0f, 2.0f, 10.0f};
+          for (int minute = 0; minute <= 60; minute += 15) {
+            const int x = left + minute * (right - left) / 60;
+            it.line(x, top, x, bottom, Color(42, 42, 42));
+          }
+          it.line(left, top, right, top, Color(42, 42, 42));
+          it.line(left, bottom, right, bottom, Color(42, 42, 42));
           for (int graph = 0; graph < 3; graph++) {
-            const int top = 52 + graph * 54;
-            const int bottom = top + 31;
+            const int legend_y = 168 + graph * 16;
             float minimum = INFINITY, maximum = -INFINITY;
             for (int sample = 0; sample < count; sample++) {
               const int slot = (id(climate_history_next) - count + sample + 361) % 361;
@@ -1006,20 +1039,14 @@ display:
               minimum = floorf((middle - range / 2.0f) / scale_steps[graph]) * scale_steps[graph];
               maximum = ceilf((middle + range / 2.0f) / scale_steps[graph]) * scale_steps[graph];
             }
-            it.print(12, top - 16, id(font_device), colors[graph], labels[graph]);
+            it.print(12, legend_y, id(font_device), colors[graph], labels[graph]);
             if (has_samples) {
-              it.printf(right, top - 16, id(font_device), colors[graph], TextAlign::TOP_RIGHT,
+              it.printf(right, legend_y, id(font_device), colors[graph], TextAlign::TOP_RIGHT,
                         "%.0f - %.0f %s", minimum, maximum, units[graph]);
             } else {
-              it.print(right, top - 16, id(font_device), colors[graph], TextAlign::TOP_RIGHT,
+              it.print(right, legend_y, id(font_device), colors[graph], TextAlign::TOP_RIGHT,
                        "Warte auf Messwerte");
             }
-            for (int minute = 0; minute <= 60; minute += 15) {
-              const int x = left + minute * (right - left) / 60;
-              it.line(x, top, x, bottom, Color(42, 42, 42));
-            }
-            it.line(left, top, right, top, Color(42, 42, 42));
-            it.line(left, bottom, right, bottom, Color(42, 42, 42));
             int previous_x = 0, previous_y = 0;
             bool previous_valid = false;
             for (int sample = 0; sample < count; sample++) {
@@ -1037,10 +1064,10 @@ display:
               previous_valid = valid;
             }
           }
-          it.print(left, 202, id(font_device), Color::WHITE, "-60 min");
-          it.print((left + right) / 2, 202, id(font_device), Color::WHITE,
+          it.print(left, 144, id(font_device), Color::WHITE, "-60 min");
+          it.print((left + right) / 2, 144, id(font_device), Color::WHITE,
                    TextAlign::TOP_CENTER, "-30 min");
-          it.print(right, 202, id(font_device), Color::WHITE, TextAlign::TOP_RIGHT, "Jetzt");
+          it.print(right, 144, id(font_device), Color::WHITE, TextAlign::TOP_RIGHT, "Jetzt");
         }
       }