Frequency is measured in hertz (Hz). A person who has hearing within the normal range can hear sounds that have frequencies between 20 and 20,000 Hz. The most important sounds we hear every day are in the 250 to 6,000 Hz range.
An issue date was added, and cheques may not be valid a certain amount of time after issue. In the US and Canada a cheque is typically valid for six months after the date of issue, after which it is a stale-dated cheque, but this depends on where the cheque is drawn; in Australia this is typically fifteen months.
By the time that you realize that a stale-dated check has cleared your account, it is probably too late for your bank to reverse the charge. The mere fact that the check is several years old does not entitle you to a refund at all, and youâre fully responsible for any problems that arise as a result, e.g. overdraft fees, other checks not clearing, etc., although your bank may decide to waive fees as a courtesy.