Specialinstrument Development AB

F-indikator

THE FUNDAMENTAL FREQUENCY INDICATOR (or the F-indicator) was developed in co-operation with Prof. Arne Risberg at the Department of Speech Communication of the Royal Institute of Technology (KTH), Stockholm, Sweden. The F-indicator is primarily intended to be used for training of the voice pitch level but the indicator can also be used for practising intonation e. g., question intonation. It is originally designed to be used for training with hard of hearing children but is of course also useful for normal hearing persons. The vibration frequency of the vocal cords is picked up with a contact microphone that is held against the throat. The display panel of the F-Indicator contains a light emitting diode display, red and green on-off buttons and two yellow buttons to set the Frequency range. There are also six red lamps, between the two yellow buttons, indication the mid frequency of the display. The yellow part of the display covers approximately one octave in frequency. The mid frequency can be changed in steps of 1/3 octave from 120 Hz to 380 Hz. Pressing the left yellow button decrease the mid frequency and pressing the right yellow button increase the mid frequency. On the rear of the N-Indicator are inputs for two contact microphones, one can be used for the teacher and one for the student (One contact microphone is delivered with the F-Indicator). On the rear is also an input for connecting a battery charger (or battery eliminator if the N-Indicator is a model without internal batteries). The F-Indicator has space for an internal rechargeable "green" Nickel-Metal-Hydride battery. The F-Indicator is delivered with a batterycharger/eliminator.