One major criticism that can be levelled at almost all small headphones supplied for use with personal stereos is that they are too bulky to be stored conveniently when not in use. Manufacturers have offered several possible solutions in the form of smaller, lighter earpieces and foldaway headbands, to name just two examples, yet still the problem persists.

However, personal stereo owners who are fed up with having to cram unwieldy headphones into small pockets now have a feasible alternative in the form of stereo earphones now being marketed by several leading Japanese companies.

Sony's representatives, the MDR-E232s (or, more memorably, the Fontopias) were the first to arrive on the editorial desk, and lengthy subjective tests revealed a surprisingly high standard of reproduction. I say 'surprisingly' because on paper the Fontopias don't stand much of a chance of competing with their larger brethren in purely performance terms. Their diminutive driver units (16mm diameter) and maximum power handling of just 0.05 watts don't exactly bode well for sound quality.

On the plus side, however, the earphones can boast a surprisingly high sensitivity (108dB/mW) and a highly creditable (claimed) frequency response of 20-20,000 Hz.

The design of the MDR-E232s is nothing spectacular: they're really just stereo versions of the mono earphones supplied with countless portable radios and cheap domestic cassette recorders, the only wonder being that it took the manufacturers so long to recognise the potential of the original design concept. What is more interesting however is the manner in which the 'phones are stored, for Sony have developed a neat and efficient plastic carrying case that enables the Fontopias to be slung into the tightest of pockets and bags without the slightest threat to their condition. The case resembles something of a cross between a yo-yo and a contact lens container, and in a sense its designers have carried the cause of efficiency a little too far, in that replacing the earphones in their protective cocoon is a delicate process that requires some care on the part of the user; hence fast stowing of the miniphones is an impossibility unless you've had them a long while or you happen to be an expert on yo-yos.

Practicalities aside (and let's face it, earphones of this type are by their very nature vulnerable and fragile no matter how carefully they're used) the Fontopias performed well under a variety of conditions.

Once you've got accustomed to the idea of speakers actually being inside your ear (and for many people this is just as big a step as going from ordinary loudspeakers to headphones) the first thing that strikes you about the Fontopias' sonic performance is the sheer sense of space in the stereo images they throw up. Admittedly, I could name half-a-dozen or so headphones capable of achieving the same or better standards of imagery, but all of these have price-tags at least three or four times that charged for the Sonys, and are considerably less comfortable to boot.

To be perfectly frank, I found the 232s ability to throw up images in, around, behind and in front of my head (as well as either side, of course), rather unnerving at first, since it destroyed many of my preconceptions as to what stereo signals were and were not capable of doing. In a sense, of course, such imagery is unrealistic in that it's rare for live concert music to arrive at the ears of the audience from either side of the auditorium, but purism apart, I found the Fontopias' imaging qualities a delight, particularly when I reminded myself that they were available for less than the cost of three LPs...

But stereo imaging isn't all the 232s are good at. As the frequency response figures suggested, they are also tonally extremely neutral for 'phones of this type. Naturally there is some not inconsiderable fall-off in bass response quite early on, but, unlike some other models available, this is not accompanied by a pronounced treble lift, with the result that the Fontopias appear to be of the mellowest-sounding miniphones around.

The 232s' limited bass response does impose restrictions on their fidelity when they're presented with a signal carrying high sound levels at both frequency extremes (reggae, for example). Having said that, the bass performance was not as poor as might have been expected from one two-thirds-of-an-inch-diameter domed speaker each side. I'd say bass was fuller and better defined than it is in perhaps half of the competing 'normal-size' miniature headphones.

More serious is the Fontopias' inability to play signal at very high levels, and this even with their high sensitivity which should in theory improve this parameter. Unfortunately, it seems that even the most undynamic signal could provoke a nasty bout of distortion from the 'phones if fed with sufficient volume. I realise that the importance of this factor will vary greatly from individual to individual, but from my point of view I found it annoying in that recently-recorded signals from a personal cassette recorder (also a Sony, as it happens) had to be played back on location at pitifully low levels in order to avoid distortion. If you're fond of monitoring (or just listening) at high levels, the Fontopias are not for you.

On the other hand, assuming you can reconcile yourself to walking about with a tiny speaker in each year, the 232s are a rewarding listening experience, if not a particularly accurate one. And, of course, they are considerably lighter and easier to carry than any of their more traditional competitors.

The Fontopias carry an RRP of £16.95 including VAT, and further information can be had from Sony (UK) Ltd., (Contact Details).