The PC speaker is normally meant to reproduce a square wave via only 2 levels of output (the speaker is driven by only two voltage levels, typically 0 V and 5 V).
For example, if your payments for March and July 2010 were each one month late, the report may continue to show (for seven years from the date after each payment was due) that you were 30 days late twice in 2010, even though the tradeline for that account also shows your payments for the rest of 2010 were made on time.
Counting Seven YearsWhen it comes to your credit report, negative information typically stays on your report for seven years. This means that late credit card payments stay on your credit report for seven years from the date the payment was missed. If that late payment eventually turns into a default, the seven years counts from the original missed payment deadline.