From Wikipedia: Bit rate often refers to the number of bits used per unit of playback time to represent a continuous medium such as audio or video after source coding (data compression). The size of a multimedia file in bytes is the product of the bit rate (in bits/s) and the length of the recording (in seconds), divided by eight.

To learn who & why the network is spammed to stop copyright file sharing, see Beware of Fake files in search results. To see examples of spam sizes & sizes you should learn to recognise (you already are starting to learn by the sounds), see Virus thread: Typical virus spam file sizes - Make a note of them (click on blue link to see). This also shows the spam is auto-renamed to match your search criteria.

Other type of audio file problem, file corruption, see mp3 Bit-Rates Versus File Sizes (click on link). This is harder for the average person to compare, however if you notice the size of the file compared to bit rate & duration of song is different to others in search results with same bit rate, then you know something is wrong. These such corrupt files might show a bit rate of 192 or 320 kbps but after downloading & playing, they playback with a bitrate of perhaps 32 kbps & you either only hear silence or noise, or chipmunks or the file will refuse to play at all.

Bitzi mostly has video file reports, but some audio file reports do exist there. Bitzi is a site which has reports on p2p sharing files. People can list files there, make reports, etc. And likewise, others can check the files in their search results by doing a bitzi lookup to see if there are any reports on that file. How to use Bitzi Web Lookup This way people can learn if there are problems with any files they find in their search results. If the file is not listed at Bitzi, then some doubt could be cast upon it. The more people who list their shared files at Bitzi or make reports on shared files they find, then the better for everyone.