B. SAC and SOAC Unaided Means Based on PTGs

By combining our database of various studies and using the original items that are also continuing items we have produced mean and 10%-90% range data for preliminary normative purposes. Some of these data were reported in 2005 by Schow, et al. but we have enlarged the database on this website. These findings show results when hearing aids are not used. Later we present outcome data for hearing aid users by PTG. There are three major samples contained in this combined database (See Figure B).

The first sample has the responses from a large health fair study which was performed at numerous locations throughout Idaho. In this sample we gathered a very large database of over 6000 persons from the general population who came to health fairs to have their hearing tested. About half, (n=3346) were found to have hearing loss based on a fence at 25 dB at 500, 1000, and 2000 Hz and 30 dB at 4000 Hz. See the support for this fence in adult hearing screening as shown in Schow (1991, Ear and Hearing). A portion of the health fair sample (n=1243) filled out SAC (1982) questionnaires and became part of our SAC mean and range data.

A second sample came from the HEARx company which is a major hearing aid dispenser located in 4 states (CA, AZ, NY, FL). The HEARx company in 2003 picked the 1982 SAC/SOAC as the best outcome tool after trying out 20 different self report outcome measures. The data summarize 286 persons fit by hearing aids in a HEARx sample.

A third sample contained here involves a stratified sample of 60 and their significant others who filled out the new 2007 computerized versions of SAC/SOAC in the summer of 2007 (Hodes, Schow, Brockett, 2009).

These three samples are in our SAC/SOAC database with information on age, gender, and hearing loss. All 3 data sets were sorted into PTGs and Figure B shows the mean SAC score for each of the three samples. The fourth bar in each graph shows the SOAC scores sorted into PTGs as obtained from only the computerized study. We have much more limited SOAC data, but fortunately the means are shown to correspond closely to SAC data. Figure C-1 shows the means of SAC scores for the 3 samples (when scores, ages and genders are combined). To be included in this graph N's of 5 or more were selected. Figure C-2 shows the SOAC scores. Section D, Figures 1-4, shows pure tone data.

In Figure B, the normal hearing means fall nicely in the middle of the normal range (0-20%). The hearing loss means cluster nicely for most PTGs (4k1, 4k2, F-2, S-1, P-1, P-2). For F-1 and S-2 there is more spread, but this seems to be explainable due to some small samples. By combining all data into a total data set, we have derived useful information for those who use SAC and SOAC in other settings and wish to have preliminary norms. Look for these in section C and Figures C-1 and C-2. Figure B shows how SAC and SOAC scores for different hearing losses (PTGs) will need to be reduced when aided to bring scores closer to or within normal limits (0-20%).


Figure 1
Figure B
(Click on Image to Enlarge)