Totally could~
No, I don't think you can actually consciously choose not to hear something.
OP, the two are at opposite ends of the power spectrum. Sumblime Chord is the highest powered bard PrC, and Seeker is one of the absolute weakest.
SC gives up a bit of performance to focus on casting, and gives you 9th level spells. That's just...amazing.
Seeker gives up all casting progression to focus on performance. But...it's overall worse than SC at performances, too, so it's a total fail. Quality beats quantity. And SC's song to increase caster level is stronger than anything Seeker has to offer. Most Seeker songs are actually quite terrible, the only good one (and it is extremely good) is the one that shuts down all spellcasting. But that's not till halfway through the awful class and it is double-edged. If you have multiple other casters in your own party, it's probably more of a nerf than a boon; if it's a martial-heavy party, it is a great choice, though.
What level are you starting at? SC can't even be entered until level 11, and Seeker's only redeeming quality is 5 or 6 levels in, so neither PrC is actually viable for a long time. If you're starting at low levels, might be better to not bother w/ either and pick something else with much earlier payoff, like Lyric Thaumaturge.