Espeak showing some warnings and Input output error

My espeak also returns similar messages:

$ espeak -v en-us+3 -s 120 -k 20 "Pray. For. Moe. Jo."
ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm_dmix.c:957:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
Cannot connect to server socket err = No such file or directory
Cannot connect to server socket
jack server is not running or cannot be started

Redirecting them to /dev/null get's rid of them but that's only hiding the messages:

$ espeak -v en-us+3 -s 120 -k 20 "Pray. For. Moe. Jo." 2>/dev/null
$ 

PulseAudio

According to this thread it looks like there is a issue with how PulseAudio is configured, specifically that there are pcm's in ALSA's configuration that aren't correct. The thead says you can safely ignore those if you like.

Specifically these messages:

ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe 
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side

The other messages are related to BlueTooth (hence the BT_...) in the message.

Specifically these messages:

ALSA lib audio/pcm_bluetooth.c:1614:(audioservice_expect) BT_GET_CAPABILITIES failed : Input/output error(5)
ALSA lib audio/pcm_bluetooth.c:1614:(audioservice_expect) BT_GET_CAPABILITIES failed : Input/output error(5)
ALSA lib audio/pcm_bluetooth.c:1614:(audioservice_expect) BT_GET_CAPABILITIES failed : Input/output error(5)
ALSA lib audio/pcm_bluetooth.c:1614:(audioservice_expect) BT_GET_CAPABILITIES failed : Input/output error(5)

In general it looks like all these messages can safely be ignored. If you're inclined to try and get rid of them I would focus my attention on if I have any bluetooth services running, and turn them off. Additionally I'd look through the ALSA configurations under /etc/alsa and /etc/pulse.

Workaround

If you want to completely disregard these messages you can run espeak ... and redirect these messages to /dev/null.

espeak -v en-us+3 -s 120 -k 20 "Pray. For. Moe. Jo." &> /dev/null