Basic Laws of Sefirat HaOmer - 3
What if one forgets to count?
If one forgets to count at night, he or she repeats the count the following day without a "bracha," and then resumes counting with a blessing that night. If one forgets to count in the daytime as well, it's "wait till next year" time as far as counting with a "bracha" is concerned. But one should continue to count on subsequent nights without a "bracha."
If one is unsure whether one counted, the nightly count should be continued, with a bracha.
How does one ask for a reminder of the Count?
Better, how does one reply to such a question? The problem is that if the response is, say, "No problem! Tonight we count forty-eight," the person who responded in that fashion has already counted(!) and may not count again (this night or day) with a "bracha."
The proper response to the above question would be "Last night we counted 'forty-seven.' By doing so, one has not counted "by accident" tonight.
What if the "bracha" were recited by an individual without knowledge of the Count, but with the intention of counting in accordance with what one hears from the rest of the congregation?
It is best to count with knowledge of the correct Count in mind, but if the counting is performed in the manner described above, the obligation has been fulfilled.
If the "bracha" was recited with the wrong number in mind, but the counter heard the correct information from the congregation, and counted correctly, has the obligation of Counting been fulfilled?
An Interesting Contrast:
On Purim, everyone else present in the synagogue listens to the blessing of the "Koreh," the Reader, answers "Amen" to it, and listens to every word of the Megillah. The "Koreh" has in mind to enable the listeners to fulfill their obligations. And it works!
During the period of Sefirat HaOmer, the Counting of the Omer, on the other hand, consider person A , let's call him "Reuven," for argument's sake, listening intently to person B , let's call him "Shimon," for argument's sake, pronounce the blessing and count. Reuven answers "Amen" to Shimon's blessing and concentrates on the count; although Shimon has in mind to enable the listener, Reuven, to fulfill his obligation, it doesn't work! And if Reuven does not count again by himself that night or the next day, he may not resume the count with a blessing.