Halotea Free is an interesting tool for generating soothing ambient sounds, which in theory could improve your concentration by helping you tune out distractions.

On launch the program displays 28 "themes", each with their own mix of sounds: wind, rain, fire, crickets, frogs, birdsong, chimes, white noise, heartbeat effects and more.

You're able to tweak the volume of every element, as well as the left/ right balance, and save the results with a click.

An optional timer turns playback off after a defined period, which could be handy if you're using the program to help you sleep.

There's a scheduler to automate future events, although bizarrely it doesn't seem able to play environmental sounds. Instead you must specify an audio file to play, program to execute or system action to take.

There's also what looks like a reasonable audio player - playlist support, 10-band equalizer, echo and reverb effects - but for some reason we couldn't get it to play anything at all.

Upgrading to one of the commercial editions of Halotea gets you features like Theme creation, editing, import and export. That's good, but the prices - $19.97 and $39.97 - seem steep.