AFAIK positional audio implementation in chromium has a number of issues that pretty much, but not entirely, break it. A year or so ago I was involved in a Chromium issue tracker and uploaded a simple javascript example showing the issues but to my knowledge nothing has been fixed.
That said, if you are rapidly playing a bunch of sounds every 0.1 seconds, it is highly likely that you are hearing digital clipping. The sum of multiple sounds playing over the top of each other is exceeding 0dBFS and causing audio artifacts.
You can try reducing the volume of your samples to make sure they are not near 0dB and making sure the length of each sample to be played rapidly is shorter than the period before the next sample will be played.
Construct has no Master Limiter effect that you can run all sounds through to prevent clipping, so you need to manage your levels carefully