A light weight, solid state 'bug in the ear' device is described which can be easily built for less than $ 13.00. The system is operated by a 9V transistor radio battery, is portable, and can be used as a regular intercom system when the 'bug in the ear' is not in use.
|Original language||English (US)|
|Number of pages||2|
|State||Published - Jan 1 1974|
ASJC Scopus subject areas
- Clinical Psychology