No sound audible (or extremely low volume) during validation of sentences

I’m running Mac OS X 10.14.5 on a 2017 iMac with a Snowball Blue microphone. So far I have been recording and attempting to validate Esperanto sentences only.

I can clearly hear my recordings being played back by my computer’s built-in speaker when I relisten to them. However, when I tried to validate sentences spoken by other Common Voice volunteers, the first five I listened to had no detectable audio at all. I marked them “No,” but I was at first reluctant to try to validate more sentences until I knew for sure whether there were in fact sound files associated with those sentences.

In other words, I thought there might be some software problem that prevents playing back a file that actually exists and, for all I know, may be a perfectly nice recording. Is it possible to have someone else relisten to those first five sentences presented to me today to confirm that the sound recordings should be deprecated?

Also, although subsequent audio files were audible on my computer, for a few of those sentences the audio volume was very poor. I wonder if you could create a facility that would send feedback to users to help them improve their recording capability.

Perhaps, also, there could be a recommendation somewhere in your initial instructions that suggests having an external microphone or,
faute de mieux, speaking very close to a computer’s built-in microphone. Maybe also recommend that the volume settings of the built-in mike and the built-in speaker should both be at about medium. That way a volunteer reader will quickly realize what is the optimal setup in her own case.

Kind regards,
Erik Bjørn Pedersen