雷鸣器（Thunder Sheet）是近代才发明的敲击乐器，属于体鸣乐器类别。最初用于剧场音乐当中，用来模仿打雷时的声音，后来亦开始应用于交响乐团中。

最初的雷鸣器是将一金属球置于大鼓鼓腔内，藉敲打或滚动制造声响，但这种方法非常不方便，后来改良为置一张金属片于大鼓的其中一面鼓皮。靠敲打大鼓的另一面鼓皮，制造震动而间接令铁片震动发声。现时则多参考锣的放置方法，由一张长于2-3米的金属片垂直在锣架上，演奏时可以利用锣棍敲打，又或者由敲击乐手将铁片前后翻动来制造声响。

运用雷鸣器最著名的例子，便是由德国作曲家理察·施特劳斯的《阿尔卑斯交响曲》中的「暴风雨」选段。

A thunder sheet is a thin sheet of metal used to produce sound effects for musical or dramatic events. The device may be shaken, causing it to vibrate, or struck with a mallet.

Thunder sheets are available from some cymbal makers including Paiste and Sabian, or can easily be made out of any scrap metal sheet. If shaken, it is highly recommended that the player wear gloves to prevent cuts on the hands. The thinner and larger the sheet, the louder the sound. The thunder sheet needs to be "warmed up" before the actual sound is desired to be heard. The player(s) will need to start slowly shaking the sheet a few seconds before quickly shaking the sheet.