diff --git a/VorleserKit/Sources/AudioEngine/AudioEngine.swift b/VorleserKit/Sources/AudioEngine/AudioEngine.swift
index ae84a4a..889934b 100644
--- a/VorleserKit/Sources/AudioEngine/AudioEngine.swift
+++ b/VorleserKit/Sources/AudioEngine/AudioEngine.swift
@@ -131,7 +131,10 @@ public final class AudioEngine {
 				nextBuffer = nil
 			} else {
 				do {
-					let samples = try synthesizer.synthesize(text: sentence.text)
+					let samples: [Float] = try autoreleasepool {
+						try synthesizer.synthesize(text: sentence.text)
+					}
+					synthesizer.clearCache()
 					buffer = Self.makePCMBuffer(from: samples)
 				} catch {
 					currentSentenceIndex += 1
@@ -146,7 +149,10 @@ public final class AudioEngine {
 				guard nextIdx < sentences.count else { return nil }
 				let nextText = sentences[nextIdx].text
 				return Task.detached { [synthesizer] in
-					guard let samples = try? synthesizer.synthesize(text: nextText) else { return nil }
+					guard let samples: [Float] = try? autoreleasepool(invoking: {
+						try synthesizer.synthesize(text: nextText)
+					}) else { return nil }
+					synthesizer.clearCache()
 					return SendableBuffer(buffer: Self.makePCMBuffer(from: samples))
 				}
 			}()