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.
What is a stale check? Quick Answer. A stale check is one that is presented for payment six months or more past the date on its face. Banks are under no obligation to cash a stale check unless it is a certified check; however, the institution can cash the instrument if it appears to be a payment made in good faith. Each financial institution may have its own policy on whether to pay or decline these checks.