Audiometer, model 1701, by Grason-Stadler, Littleton, New Hampshire, U.S.A., 1970-1980 Audiometer, model 1701
Monaghan pulmonary function analyser (electronic spirometer) model 403, by Hospal Medical Corporation, Colorado, USA, 1977 Monaghan pulmonary function analyser (electronic spirometer) model 403 1977
Audiometer, model 1715, by Grason-Stadler, Littleton, New Hampshire, U.S.A., 1970-1980 Audiometer, model 1715 1970-1980