Chanting in your ears

This is another story from my grandmother's wake/funeral at the parlor; and it is not really any scary story but rather a bizarre one as it was a little something a few experienced.
Anyway, here goes...

My grandmother's funeral rituals were conducted the Buddhist way; although there was a touch of Taoism as well (don't ask me why just yet, let's just say, there's a confusion of religion among the people who organized it )
My maternal grandmother herself is a Taoist.

Anyway, the main ritual was supposedly Buddhism, and they are simple and fuss-free.
There is this speaker they turned on in the hall near the coffin, which plays the Buddhism chants on repeat mode.

As most of us descendants are there most of the time for the five days of the wake, we could constantly hear these chants. It's like the chants were just replaying itself or stuck in your mind forever as you listen to them.

That was the explanation I offered when my mum and two aunts told me about their story that they heard the chanting when they got home at night.
All of them were staying in the same house; the house that grandmother used to stay and they claimed that each of them heard the chanting on different accounts.
One of them heard the chants like it was being played directly near them when they were in the shower.

Another claimed that they heard the chanting in the bedroom as she was getting ready for bed.
And lastly, another heard the chanting in the living hall. Their claims were backed up by cousin sister who went home with them.
There was a point when all four of them were in the hall and they just heard the chanting sound exactly like it was played on the radio at the parlor!
They were chatting when they all heard it, and they all froze for a moment, thinking that only one of them heard it.

When they looked at each other, they knew that ALL of them heard it and there were only four of them inside the house.
They looked at one of the aunt who had this radio inside her room and she had this exact same tape which played the Buddhism chants as the parlor, and she used to play them quite often when she needs peace of mind. Of course, the last time she played it was when grandmother was in a critical condition in the hospital.

Everyone automatically gave her that look which did not say anything but somehow meant, "Was that your radio/tape?"
She shook her head, and she walked into her room and then came out saying, "I stopped playing the tape because my radio ran out of batteries. There is no way this sound came from my radio"

It was at that point everyone was speechless, and it was also at that exact same point when the chanting in their ears stopped.

When they told me the story, my mum suspected that it could be that grandmother followed them home and since she was being led the Buddhism way, she is being surrounded by prayers.

As usual, I do not take a doubtful or skeptical stand on something like this, but I can offer a simple explanation which is more scientific in nature.
When a specific sound goes on for a while and on repeat mode, it tends to stay on the mind for a while as it creates that kind of resonance/wave lengths (whatever that meant in physics, you can check that up).

Whether grandmother really followed them back or not, that is something none of us would ever know and I'd say to leave it at that.