The hospital I applied to volunteer at called me and asked when I was available and after I told them my times, my baby sister screamed “mama” and all. The person on the phone was silent but then said she’ll look to see what they have available. Did this ruin my whole chance at volunteering at this hospital?
Well, you could send the volunteer coordinator an email apologizing for your sister’s interruption, and reiterating the times you are, in fact, available. Mention again how excited you are at the prospect of volunteering with them. Keep it friendly and very professional.
@Groundwork2022 I don’t think their email is listed on the website I only see numbers
Now you’ll remember to close the door (lock?) If you’re having a professional interview/conversation. 
That being said, I don’t think your baby sister screaming will matter. (remember when the North Korea expert’s toddler rolled into his national TV interview?)