为什么mpg123 在bash能发出声音,而用cron定时运行,只能运行确没有声音输出?

wxd_b994832

在bash下运行输出如下:
High Performance MPEG 1.0/2.0/2.5 Audio Player for Layer 1, 2 and 3.
Version 0.59r (1999/Jun/15). Written and copyrights by Michael Hipp.
Uses code from various people. See 'README' for more!
THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY! USE AT YOUR OWN RISK!
Title  : change parteners                Artist:
Album  :                                 Year  :
Comment:                                 Genre : Unknown

Directory: /home/wxd/mp3/
Playing MPEG stream from song11.mp3 ...
MPEG 1.0 layer III, 128 kbit/s, 44100 Hz joint-stereo




我的crontab表如下:
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.12865 installed on Wed Jan  4 22:32:12 2006)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)
*/2 22 * * * /usr/bin/mpg123 /home/wxd/mp3/song11.mp3

运行以后出现:
You have new mail in /var/spool/mail/wxd
内容为:

Date: Wed, 4 Jan 2006 22:40:00 +0800
Message-Id: <200601041440.k04Ee0V4012959@localhost.localdomain>
From: root@localhost.localdomain (Cron Daemon)
To: wxd@localhost.localdomain
Subject: Cron <wxd@localhost> /usr/bin/mpg123 /home/wxd/mp3/song11.mp3
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/home/wxd>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=wxd>

High Performance MPEG 1.0/2.0/2.5 Audio Player for Layer 1, 2 and 3.
Version 0.59r (1999/Jun/15). Written and copyrights by Michael Hipp.
Uses code from various people. See 'README' for more!
THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY! USE AT YOUR OWN RISK!
Title  : change parteners                Artist:
Album  :                                 Year  :
Comment:                                 Genre : Unknown

Directory: /home/wxd/mp3/
Playing MPEG stream from song11.mp3 ...



为什么没有声音呢???????????????

对比一下好象在cron下没有最后一句话???
MPEG 1.0 layer III, 128 kbit/s, 44100 Hz joint-stereo



各位高手能分析一下什么原因吗???