Some hearing instruments are equipped with technology that allows the instrument to re-position highfrequency

input information in a lower frequency output register. Using Audioscan equipment running V3.4 software

or higher, this functionality can be tested using one of three modied versions of the Speech-std (1) test

stimulus (Speech4000, Speech5000 and Speech6300) which are available in the Speechmap stimulus menu.

In each of these modied test stimuli, the 1/3 octave band

levels above 1000Hz are reduced by 30dB, except for an

isolated 1/3 octave band centered at the frequency indicated

in the selected test stimulus’ name. With these

reduced band levels, the resulting input LTASS produces a

distinct “cavity” between 1000Hz and the selected high

frequency band, as seen at left.

The International Speech Test Signal (ISTS) is now available

as a stimulus option in Speechmap

Flash drives on RM500SL devices can be updated directly

from the Audioscan website instead of burning a CD rst.

Fitting targets can be selected and viewed through the

Viewport Audibility screen of Speechmap

The aided LTASS obtained from a frequency lowering

hearing instrument should re-position the highfrequency

input band at some lower frequency area

within the input stimulus cavity, as seen at right.

Obtaining such a test result veries the frequencylowering

capabilities of the hearing instrument.