保持同一水平 meaning in English

keep on an even keel

Svm （ smart volume management ? ）， adjusts the playback volume of all the tracks on your playlist so they will remain at the same level without you reaching for the volume control between songs
智能音量管理：自动调整所有曲目的音量使之保持同一水平，无论它们录制时音量大小。
" i believe that we should plan for further increases in tobacco excises for a period ahead , so as to keep the level of tax increasing in real terms and i am discussing such a formula with the minister for health and children
“我认为我们应该为今后一段时期制定进一步增加消费税的计划，从而与实际税率增加保持同一水平，我现在正在同健康与儿童部长探讨这样一套方案。