Walkabout tape players have muffled the ears and weighted the waistbands of joggers, gardeners, students and sunbathers for almost a decade now. Over the years, they have become smaller, lighter and fancier.

The electronics engineers at Consumer Reports recently tested 31 players -- from basic tape units that sell for $50 and under to combination tape player/radios at $200.

The lower-priced players are often bigger and bulkier than higher-priced models, but low price doesn't always mean low quality.

Most of these small-sized tape players are capable of good tape-playback performance. The best were nearly as good as a moderately priced, full-sized cassette deck.

Unfortunately, a good deal of that performance goes to waste when you actually walk around with one of these players. For one thing, a walkabout's tiny headphones just can't deliver the wide range of sound that the players are capable of reproducing. Even the best headphones degrade the sound quality significantly.

But that doesn't mean the sound through the headphones will be unpleasant. Even mediocre headphones create a "superstereo" effect that often draws your attention away from defects in the sound.

Moving around with a walkabout on your belt may increase the amount of tape flutter -- an unpleasant wavering of the sound caused by fluctuations in tape speed.

The FM radios were just as impressive as their tape players. In nearly every case, they did a fine job of bringing in weak signals, picking out signals from a crowded radio band and screening out spurious signals.

But the radios may not be a suitable accompaniment for a couple of laps around the jogging path. Walkabouts use the headphone wire as the radio antenna. Moving around may cause the program to fade in and out.

The Aiwa HS-T500 was the best of the tape player/radios. But many others performed just as well, and were cheaper than Aiwa's $185 list price. The good quality of Sony's WM-F41, and its low $45 price tag, earned it a Best Buy rating.

Among the tape-only models, the Aiwa HSG600 was top-rated, although it lists for $150. The Realistic SCP-19 from Radio Shack and the Sanyo MGP 44 sounded nearly as good and cost about half as much.

If you jog at the beach or in the rain, consider two from Sony's "Sports" series -- the WM-F107 ($230 list) and WM-75 ($110 list). Their plastic housing seems especially rugged, and their tape door and controls are sealed against moisture. They're likely to be more rain- and moisture-resistant than most.

All the tested models have printed warnings that say it's possible to play some walkabouts loud enough and long enough to endanger your hearing. Such warnings are well worth heeding.