Radio Shack has infrared wireless stereo headphones on sale for $19.99. I bought a set last time they were on sale, and can report that although they are kind of chintzy and not the most comfortable headphones I've ever tried, they're reasonably good for watching porn (or anything else) without disturbing or alerting housemates, neighbors, etc. They also let you hear how much screwing around with the audio some porn producers engage in, and occasionally funny background noises that you wouldn't ordinarily hear, unless you ordinarily watch porn with your TV's volume knob on 10.

They use Ni-Cad batteries, so you have to make sure to fully charge them before you first use them, then let the charge run all the way down each tim before recharging them.

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