Does one fulfill the Mitzva of hearing Megilla if it is read with microphone and loudspeakers?

According to almost all current authorities, the electronic system duplicates, but is not considered the original voice, and therefor hearing the Megilla in this way is not valid. If one is in a situation where hearing the Megilla "live" is impossibe (e.g. hospitalization) one may rely on the opinions that a telephone or loudspeaker voice is valid.