He amplified sound with the use of electronic equipment.

他用电子设备放大声音。

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What seems to happen, the researchers reckon, is that when a screech on a chalkboard is generated, the sound is amplified within our ears to painful effect.

研究者们顺理成章地得出这样一个结论：当黑板被挂擦时，该声响在我们的耳内放大，加剧了痛苦。

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Licensed by MLG, the high performance PX22 features cross platform capabilities and amplified stereo sound.

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If you have the sound coming out of an amplified device, you will have excellent range.

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The school's PA system was still on from the morning announcements and every sound in the building was amplified.

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