When I travel I love to sketch in watercolor. When I go to a new place I'm always torn, do I explore more or take the time to sit down and do a sketch. My daughter with her dry sense of humor, coined a phrase, when I schlep all my sketching stuff around, all day to never sit down and do a sketch, says, "Well today it looks like you did more performance art than real art!" Apropos for someone who actually is a performing artist and sometimes a smart @#%. Sometimes you just feel more compelled to explore. But there are the times when you purposefully set out to sketch or as you are exploring feel compelled to capture something. I love the process so I like to take my time and not rush through the sketching experience. I can take anywhere from one hour to two. More than two hours is pushing it for me.
I can zone out and focus on what I'm doing, but I'm still able to enjoy the ambiance of my surroundings, especially sound. I'm focused visually on what I'm sketching of course but the sounds are an extra bonus. Sometimes not though, I've started sketching only later after I've gotten started to be accompanied by tree trimming, mowing and leaf blowing! Not so much of this traveling though.
The locations I recently sketched in Venice, I heard the water lapping in the canals, gondoliers, children playing in the squares, church bells, cafe noise, and a din of Italian being spoken. All of this just enhances and makes sketching more enjoyable.
Then there are the smells, if you are sketching at or near cafes, it hard to stay focused if you are sketching before lunch!
All the senses for me are engaged while sketching, sight, sounds and smells. When I get home and look back at my sketches I can recall all these experiences, something a photo can never do, because we take the photo and move on. Sketching forces you to be present and experience our surroundings.