You may want to add fade in and fade out effect to an audio. And you may want to adjust volumn of part of your audio. AudioEditor freeware can help you. Please read the step by step tutorial as below:
How to fade selected audio
Step1: Open an audio, and select the beginning of audio.
Step2: Click Fadein button, you may listen the volume to the end of the selection ramping up.
Step3: Then, plesase select the end of audio.
Step4: Click Fadeout button, the volume to the end of the selection ramping down.
Step5: When you finish audio editing, please adjust audio settings and save it.
How to adjust selected audio Volume
Step 1. Open an audio, and select audio.
Step 2. Click Increa button, you may listen the volume over the entire selection increase.
Step 3. Click Decrea button, the volume over the entire selection decrease.
Step 4. When you finish audio editing, please adjust audio settings and save it.
Tips: To adjust the zoom level of the main waveform, use the zoom slider. Clicking the - or the + buttons on the end will zoom out or in by one step, respectively.