Recorded Sound Using MP3 Players

We have projects that use canned sound chips and recordable sound chips. But these just provide a single, short sound.

When your sound needs expand (e.g. longer sound track, stereo, higher quality) you start to look for other forms of sound storage, such as Compact Disks and MP3 players.

----------
---------- 
 

What Is MP3?

MP3 is a standard by which audio information can be converted into digital form for storage, processing, and playback.

Portable MP3 players have become common, giving the user hours of music or speech in a small, portable package.

For more information on MP3 sound storage, please see: 

 

What Are The Tradeoffs?

The bit rate is variable for MP3 files. The general rule is that more information is included from the original sound file when a higher bit rate is used, and thus the higher the quality during play back. In the early days of MP3 encoding, a fixed bit rate was used for the entire file.

Bit rates available in MPEG-1 Layer 3 are 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s, and the available sample frequencies are 32, 44.1 and 48 kHz. 44.1 kHz is almost always used (coincides with the sampling rate of compact discs), and 128 kbit/s has become the de facto "good enough" standard

Common MP3 parameters are:

So, how much sound could you get into a 16MB player? 
16 megabytes = 16 * 1024 * 1024 * 8 = 134217728 bits
134217728 bits / (128 * 1024) / 60 = 17 minutes
As a random sample, I checked the file "avalanche.mp3" downloaded from the site of the artist Thea Gilmore (http://theagilmore.com). The song plays for 4 min 21 sec and takes up 1.99MB of storage (bit rate is 64 kbit/s). At that rate, you could record over half an hour of stereo. 

 

A Cheap MP3 Player

In June 2006, a particularly cheap MP3 player was spotted at some surplus outlets.

[photo]


Sources:
vendor part number description price
Marlin P. Jones #16520 MI MP3 PLAYER $4.95 [6/2006]
B. G. Micro #AUD1081 MP3 player $5.95 [6/2006]

Halloween-L member Nitefin bought one of these players early and reported to the list on the battery life.

Nitefin reported that when the battery ran out, "it did not drag or slow down it just shut off."

----------

Thank you for visiting. Your comments are welcome.
[back] . . . [paper and pen] . . . [tip jar]

©Copyright 2006 by The Wolfstone Group. All rights reserved. You must read and abide by our terms of service.