You could delete sound recording on Huawei P8 Lite with factory reset.Your smartphone already comes along with a factory reset choice. When you select it, a process will take place that will ultimately place your device in its initial state; therefore, there will be no past data present and device will be like "New".

Hi DougB. Which sound recording app are you using? There's an option on the sound recorder app to delete previously recorded sounds. If you see them, try tap and hold and see if a pop-up menu with Delete option shows up.