I sometimes (every few months?) will have the TiVo sound effects go out on me. This often will happen when there is a burst of static sound--I assume that there has been an audio glitch/overload. What fixes it for me is to go into the TiVo box's audio settings, change the setting from PCM (my default audio setting) to Dolby, exit back to the main screen (or the My Shows screen may be enough), then go back into the audio settings again and change back to PCM.
Separately, it sounds like the 7 pm occurrence was your being thrown back into the beginning of the channel's TiVo buffer.
As to the soundbar playing extraneous audio, I sometimes have had another device (my laptop) take control of the audio on my soundbar--it seems that when something causes the TV's output to the soundbar to get interrupted, the soundbar looks for another input and finds the laptop's. I've learned--after being surprised by this a bunch of times, not knowing what sound that is and coming from where--to grab the soundbar's remote and to manually change the input back to the TV.
Separately, it sounds like the 7 pm occurrence was your being thrown back into the beginning of the channel's TiVo buffer.
As to the soundbar playing extraneous audio, I sometimes have had another device (my laptop) take control of the audio on my soundbar--it seems that when something causes the TV's output to the soundbar to get interrupted, the soundbar looks for another input and finds the laptop's. I've learned--after being surprised by this a bunch of times, not knowing what sound that is and coming from where--to grab the soundbar's remote and to manually change the input back to the TV.
