in such situations, the best thing to do is…
ask your LOR!
Also, the avielus of Sefira is NOT Deoriasa. Meaning, in the first original sefira, it was a time a joyous albeit serious preparation, getting ready to recieve the Torah.
Only AFTER were the Talmidim or R’ Akiva niftar, and therefor Chazal instituted Avielus. Hence the Avielus we observe in this time is not complete (and only focused on)Avielus.
Therefor i don’t believe one can make the connection of a being allowed to listen to music during Sefira, and an Avel being allowed to listen.
but once again… ask your LOR!