diff --git a/frontend/src/views/DiaryView.vue b/frontend/src/views/DiaryView.vue
index 2ccc7da8..3779e5a7 100644
--- a/frontend/src/views/DiaryView.vue
+++ b/frontend/src/views/DiaryView.vue
@@ -2335,50 +2335,37 @@ export default {
 
         startCheckingTime() {
             if (this.timeChecker) clearInterval(this.timeChecker);
+            this.playedActivityMarks = [];
             this.timeChecker = setInterval(() => {
-                const currentTime = new Date().toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit', second: '2-digit' });
-                // Zeit-Check Tick
+                const now = new Date();
+                const currentTime = now.toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit', second: '2-digit' });
+                const currentHHMM = currentTime.slice(0, 5);
                 if (!this.trainingStart || !this.trainingEnd) {
                     return;
                 }
-                let startCheckTime = this.trainingStart;
-                let endCheckTime = this.trainingEnd;
-                const startCheckTimeBlocks = startCheckTime.split(':');
-                if (startCheckTimeBlocks.length < 3) {
-                    startCheckTime = `${startCheckTime}:00`;
-                }
-                const endCheckTimeBlocks = endCheckTime.split(':');
-                if (endCheckTimeBlocks.length < 3) {
-                    endCheckTime = `${endCheckTime}:00`;
-                }
-                if (startCheckTime && currentTime === startCheckTime) {
-                    this.playBellSound();
-                } else if (endCheckTime && currentTime === endCheckTime) {
-                    this.playBellSound();
-                } else {
-                    // Nach letzter Aktivität (Ende) nochmal Glocke
-                    try { this.calculateAllItemTimes(); } catch (e) { }
-                    const items = Array.isArray(this.trainingPlan) ? this.trainingPlan : [];
-                    const lastItem = items.length ? items[items.length - 1] : null;
-                    const lastEnd = lastItem && lastItem.endTime ? lastItem.endTime : null;
-                    const lastEndSS = lastEnd ? (lastEnd.length === 5 ? lastEnd + ':00' : lastEnd) : null;
-                    const lastEndMM = lastEndSS ? lastEndSS.slice(0, 5) : null;
-                    const currentHHMM = currentTime.slice(0, 5);
-                    if (lastEndSS && (currentTime === lastEndSS || (currentTime.endsWith(':00') && currentHHMM === lastEndMM))) {
+
+                const bellTimes = [this.trainingStart, this.trainingEnd].filter(Boolean);
+                for (const bellTime of bellTimes) {
+                    const key = `bell:${bellTime}`;
+                    if (currentHHMM === bellTime && !this.playedActivityMarks.includes(key)) {
                         this.playBellSound();
+                        this.playedActivityMarks.push(key);
                     }
                 }
-                // Aktivitätszeiten (Startzeiten) aus Trainingsplan prüfen
+
                 try { this.calculateAllItemTimes(); } catch (e) { }
                 const items = Array.isArray(this.trainingPlan) ? this.trainingPlan : [];
-                const startTimesSS = items
-                    .map(it => (it && it.startTime ? (it.startTime.length === 5 ? it.startTime + ':00' : it.startTime) : null))
+                const startTimes = items
+                    .map(it => (it && it.startTime ? it.startTime.slice(0, 5) : null))
                     .filter(Boolean);
-                const startTimesMM = startTimesSS.map(t => t.slice(0, 5));
-                const currentHHMM = currentTime.slice(0, 5);
-                const isMatch = startTimesSS.includes(currentTime) || (currentTime.endsWith(':00') && startTimesMM.includes(currentHHMM));
-                if (isMatch) {
-                    this.playThumbSound();
+
+                for (const startTime of startTimes) {
+                    if (startTime === this.trainingStart) continue;
+                    const key = `thumb:${startTime}`;
+                    if (currentHHMM === startTime && !this.playedActivityMarks.includes(key)) {
+                        this.playThumbSound();
+                        this.playedActivityMarks.push(key);
+                    }
                 }
             }, 1000);
         },
@@ -2386,7 +2373,11 @@ export default {
         playBellSound() {
             if (!this.soundEnabled) return;
             try {
-                this.bellSound && this.bellSound.play();
+                if (this.bellSound) {
+                    this.bellSound.pause();
+                    this.bellSound.currentTime = 0;
+                    this.bellSound.play();
+                }
             } catch (e) {
                 // ignore
             }
@@ -2395,7 +2386,11 @@ export default {
         playThumbSound() {
             if (!this.soundEnabled) return;
             try {
-                this.thumbSound && this.thumbSound.play();
+                if (this.thumbSound) {
+                    this.thumbSound.pause();
+                    this.thumbSound.currentTime = 0;
+                    this.thumbSound.play();
+                }
             } catch (e) {
                 // ignore
             }