pcm.!default {
    type plug
    slave {
            pcm {
                    type bluealsa
                    device E4:22:A5:58:09:95
                    profile "a2dp"
            }
    }
    hint {
            show on
            description "Calisto"
    }
}
ctl.!default {
    type bluealsa
}

aplay soundfile.wav

ALSA lib conf.c:4974:(snd_config_expand) Unknown parameters 0
ALSA lib control.c:1373:(snd_ctl_open_noupdate) Invalid CTL default:0
ALSA lib conf.c:4974:(snd_config_expand) Unknown parameters 1
ALSA lib control.c:1373:(snd_ctl_open_noupdate) Invalid CTL default:1

0: ALSA: default device
1: ALSA: bcm2835 ALSA
2: PulseAudio: default

sudo modprobe snd-aloop

pcm.looptest {
        type plug
        slave {
                pcm {
                        type bluealsa
                        device E4:22:A5:58:09:95
                        profile "a2dp"
                }
        }
        hint {
                show on
                description "Calisto"
        }
}
ctl.looptest {
        type bluealsa
}

defaults.pcm.card 1
defaults.pcm.device 0

linphonec> soundcard list
0: ALSA: default device
1: ALSA: bcm2835 ALSA
2: ALSA: Loopback
3: PulseAudio: default

../../../src/asound/../shared/ctl-client.c:107: Connecting to socket: /var/run/bluealsa/hci0
../../../src/asound/../shared/ctl-client.c:237: Getting transport for E4:22:A5:58:09:95 type 0x81
ALSA lib ../../../src/asound/bluealsa-pcm.c:679:(_snd_pcm_bluealsa_open) Couldn't get BlueALSA transport: No such device or address
capture looptest open error: No such device or address
Loopback initialization failure.