Two months ago I reported on the problem of unsolicited sonic assaults in public spaces in Washington -- namely, Lafayette Square {"That Amplifier in Lafayette Square," Close to Home, Oct. 4}. I was advised at the time that the Environmental Protection Agency, upon complaint of a citizen and subsequent notification by the police, supplied the monitoring device that determined whether the sound was within legal limits. This was incorrect.

In point of fact, EPA eschews all responsibility. It is the Environment Services Department of the D.C. Government which entertains complaints of this kind. For convenience, these are vetted by a Mr. Pike of the Housing Division.

Mr. Pike has a monitoring device which he brings to the complaint area. If there are 200 or more persons producing the noise and a permit has been issued, there will be no interference in whatever sonic mayhem emerges. If there are 199 persons or less, their combined decibel levels must not exceed 70 within one meter. This reasonable system has yet to be applied to a public park. Its only application to date has been to nightclubs. On the complaint of a neighbor Mr. Pike or his designee comes to the allegedly offending nightclub, closes its front door and sets his device one meter therefrom. Depending on a presumably previous head count of the merrymakers within, he makes his fateful determination.

I am happy to clear this up. -- James W. Symington