Yes. The listening environment and equipment used plays a huge part in how that might affect your listening experience. Using a higer bitrate for the MP3 will cut down the difference, but it'll still be noticable.
Leo
I think alot of applications now default to 128kbps or 192kbps when ripping, which gets close to CD (certainly with cheap headphones on the bus).
There are also lossless digital formats, e.g. flac, but then they take up more space.