They do a decent job of isolating sound due to the seal that's formed between the tips and your ears, but they don't block everything out. During quiet tracks, you can still make out external noise if people around you are talking, for example, but for the most part they do a great job of blocking most external noise so that you can hear subtle sounds while outdoors or on public transport.
The Image S4A II headphones that we looked at are for Android, and they have a four-pole plug along with an inline control that can pause and play music with one tap (and answer calls), as well as skip tracks with multiple taps - though you'll need to install Klipsch's app from the Play store. The cord is flat and didn't get tangled, even when we just threw the headphones in our bag without caring. You can also get an iPhone version of these headphones (called Image S4i).
Apart from the issue we had with them falling out of our ears occasionally, we think these headphones are great. Their sound was superb to our ears, for all types of music, providing output that sounded clear, vibrant and true to the source.
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