I am no expert on this subject.
What I can suggest and that has worked well for me.
Whenever I add audio on the timeline, any format, I select this and open in AudioEditor or WavEditor any adjustment to ensure that the file will be renewed.
Also in the timeline to adjust the volume position in which the yellow wave peaks almost disappear. AMD-FX 8350 / 8GB DDR3
SSD SUV400S37240G / 2-HD WD 1TB
AMD Radeon R9 270 / AOC M2470SWD
Windows 7-64 / PD16 Ultimate

1st, I tried to decrease globally Audio WAV track level on the timeline by 2 dB, in a way than the yellow wave peaks disappear. I got again some audio peaks when burning DVD. After I decreased globally WAV track level on the timeline by 5 dB. I got some peaks again.

So as M. ''PlaySound'' mentioned, I select Audio WAV track and open in WavEditor and made adjustment but it creates some artefact between two pasted audio files.
I tried to set at Dolby and after LPCM (not DTS cause I'd like to get a stereo mix). Both options don't resolve the issue.
I tried also to set the quality of video encoding at HQ and Intelligent adjustment. All the same.

So, do anybody knows, in the process of burning DVD, what I have to do to avoid these peaks (as I said, original WAV files are really clean). If I can only decrease the original level by -15dB or more to avoid peaks when burning DVD, it's not a real solution cause it's a musical video with acoustic jazz music (sound will become poor even if peaks disapear). Does anybody had this kind of problem?
Thanks to provide me some solution to this issue! Chris

You must make sure the audio levels are correct on the timeline before you go to the Create Disk Module.
The Create Disk Module may are may not adjust the audio level to the Disk. I do not know for sure.

You have little or no control of the audio level in the Create Disk Module. The only thing you can select is the audio format (LCPM) for the Disk at the 2D disk tab.

That would insure that you have WAV audio on the Disk.

For me Dolby Digital is OK.
Carl312: Windows 10 64-bit 8 GB RAM,AMD Phenom II X4 965 3.4 GHz,ATI Radeon HD 5770 1GB,240GB SSD,two 1TB HDs.

You are creating MPEG2 files (HQ) first?

This already shows the failure of the audio?

Or the problem appears after creating the DVD?

I use another sofware to create DVD-video, here PD13 have low image quality must use quality Smart Fit.

With audio seems fine with stereo audio or 5.1.

Report:
today I made DVD project, I used 6 audio songs in M4A format, such as experience and 1 MP3 to complete.
I saved in MPEG2 (DVD) file.
The M4A audio was perfect.
It is extra work to convert the audio to M4A, but worth it if it works well with PD13.
The size of the M4A file is the same for a little better quality in my opinion.
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The MP3 has failed when it passes a transition or effect "sometimes", and other little things, so I saved the first audio using WaveEditor or AudioDirector, which solved the problem for me.
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When I have 2 or more songs together in the timeline I saved in a single file first, use Produce Range.
in this case dispense WE or AE.
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Note:
The PD. failed in MP3 audio, only in projects that use SVRT.
Projects that leads to rendering the video without problems for audio, MP3. AMD-FX 8350 / 8GB DDR3
SSD SUV400S37240G / 2-HD WD 1TB
AMD Radeon R9 270 / AOC M2470SWD
Windows 7-64 / PD16 Ultimate

The best solution I found to resolve audio peaks when burning DVD is here : If you import an audio non-compressed musical track (as WAV or AIFF) and if the origial level have a good modulation (between -5db and -1db / never above -1 dB), so if it is going to play on the TV, decrease all the track by -12dB. The peaks should never go above - 12db...that's actually a network standard. Audio that peaks too high will distort. I do the test and it sounds clean now. Sound is a bit weak but with a light boost at 100 Hz + 1KHz and sometimes 3K Hz, it works.

Check also if your Windows audio device settings are not too high. Some test will be welcome, but at the middle, it seems OK.
I didn't check Intel Quick Sync Video.

If it is going to play on the Web, and you import an audio non-compressed musical track (as WAV or AIFF) and if the origial level have a good modulation (never above -1 dB), decrease all the track by -6dB. The peaks should never go above - 6db (between -8db and -6db). I don't already do the test but it makes sense.

LPCM works well for me.

Tech Support said to me that the audio format in DVD in .VOB file is AC3. Thanks to all contributors and Tech Support. If You had other cue about audio, please share it. By example, Can I change all the editing audio points at the same time in the Time line (and not one by one)?