I have noted an issue whereby the sound will glitch or stop momentarily when a conversation option is selected. It is most obvious when there is music in the background and upon either mouse clicking or keyboard selecting a conversation response the sound will noticeably cut and then resume. It doesn't happen every time, but is frequent and persists through reloads and restarts of my system.
While I could not find others on this tech support forum with the issue, it was noted in the Pillars thread on the SomethingAwful forums, suggesting that it is not unique to my system.