wxml

<view class='voice'></view>

css

.voice {
  display: block;
  width: 212rpx;
  height: 238rpx;
  margin: 0 auto;
  background: url(http://clients-80105.oss-cn-hangzhou.aliyuncs.com/%E8%90%8D%E8%90%8D%E4%BA%BA%E8%84%B8%E8%AF%86%E5%88%AB/voice.png) 0 0 no-repeat;
  background-size: 1272rpx 238rpx;
  animation: step 2s steps(6) infinite;
}

@keyframes step {
  100% {
    background-position: -1272rpx 0;
  }
}