Experts agree that listening to music above 85dB can cause hearing damage. Most parents probably remember their parents telling them to turn the music down. The difference nowadays, however, is that kids (and grownups) are listening to excessively loud music piped directly into their ears via the ubiquitous earbud headphone and parents don’t know when to yell “Turn it down!” The modern solution is headphones from iHearSafe which always remain below the 85dB level no matter how high the volume is cranked up.

You can create a custom iPhone ringtone from most iTunes songs by purchasing the song for 99 cents, downloading it, choosing your start and end points using the iTunes software, then buying your custom ringtone from iTunes for another 99 cents. For details on this iTunes feature, read Dave Taylor. Chris Pirillo however, has a different method that bypasses paying iTunes and lets you create a ringtone from any song in your iTunes library for free.

The new iTunes 8 comes with a recommendation engine named Genius. If you give it permission to read your music library (which will take a bit of time, depending on how many songs you have), Genius will create playlists for you based on a single song as a seed and recommend songs from the iTunes Music Store. Learn more at Apple and at PC World.

Using free tools, Tinkernet’s Daniel Davis explains how to create an Internet radio station that all your friends can listen to. The tools needed are Winamp, Shoutcast DSP Plugin, Shoutcast Sever, and a supply of digital tunes to play. Sorry, today’s tip is for Windows users only.

Ever wonder about downloading YouTube videos onto your iPod? The problem is that YouTube (and most other video sharing sites) uses a Flash format, and your iPod needs a QuickTime format such as MP4. The solution is a piece of software that will assist with the video download, do the format conversion, and place the converted file in your iTunes folder for easy transfer to your iPod. Michael Arrington of TechCrunch recommends iTube for Windows or PodTube for Mac.

There are a variety of ways to convert an iPod from Windows to Mac, depending on how much metadata (such as playlists, album art, ratings, and date added) you want moved, and how your Windows iTunes library is configured. To transfer with CDs or DVDs, use iTunes Backup. To transfer a lot of music quickly (but not the metadata) try this technique from Cnet.com. Or, to use the iPod itself as a transfer hard drive, with these instructions from Apple.

Did you know that you can put notes, text files, ebooks and webpages on your iPod for portable reading? And you don’t need to worry about how to convert them, because iPodNotes does it for you. Simply name a URL or a local text file, and iPodNotes creates iPod Notes files. Make sure that “Enable Disk Use” is checked in iTunes, move the created files into your iPod Notes folder, and sync.

Codec (short for compressor/decompressor) is a compression format used in video, such as MPEG-4 or DivX.. Your computer media player (for example, Windows Media Player, QuickTime or iTunes) should recognize the codec required for a particular video, and play the video automatically. If it does not, you will need to find and download the correct codec yourself. Here are some resources to help you find one: Video Help or Movie Codec.

Although your portable music player may have come with earbuds, there’s a whole world of headphone choices that provide better acoustics than the usual freebies. Before you buy, learn headphone lingo and the difference between technologies such as noise-reducing and noise-canceling at these buyer guides: CNET Headphone Buying Guide and HeadRoom Selection Guide.

Leaving your iPod in a hot car will quickly eat up its battery charge. It’s best to leave your portable music player in the trunk, where it is likely to be cooler than in the glove compartment or passenger cabin For more tips on preserving iPod battery life, read “iPod Tips: Play On – Get More Battery Power From Your Player” .