What is the ruling on my suhoor after hearing a sound resembling the adhan, while being certain that the time for Fajr has begun, and continuing to eat until I hear the adhan clearly?

The decisive factor for the time of Imsak (abstinence) is the true dawn, not hearing the voice of the mu'adhdhin. However, it is permissible to follow a just mu'adhdhin who is knowledgeable of the entry of the time. If you were certain that the time of Fajr had begun and then continued your suhoor, then your fast for that day is not valid. But if you meant that it was near Fajr, then there is nothing against you.