Results from the Dutch speech-in-noise screening test by telephone

Abstract

Objective: The objective of the study was to implement a previously developed automatic speech-in-noise screening test by telephone (Smits, Kapteyn, & Houtgast, 2004), introduce it nationwide as a self-test, and analyze the results.

Design: The test was implemented on an interactive voice response system, which can handle multiple lines. The test measures the speech reception threshold in speech-shaped noise by telephone (SRTTn) in an adaptive procedure using digit triplets as speech material. The test result is given as either good, insufficient, or poor. Questions about age, sex, and subjective rating of hearing were included in the test. The test was introduced as the National Hearing test and publicity was generated. In the first 4 mo, 65,924 people took the initiative and dialed the test. The possibility to use mobile phones was disabled because of significant worse results (0.7 dB) with that telephone type.

Results: After applying exclusion criteria, results from 39,968 callers were analyzed. Seventy-five percent of the callers were older than 44 yr of age. Starting at about 45 yr of age, there is an increase in SRTTn with increasing age. SRTTns for men are significantly worse than SRTTns for women for age groups 50 to 54 and higher. Older people tend to rate their hearing better than might be expected from their SRTTn. However, after converting the mean SRTTn values per age group and per subjective score to percentile values, the values remain constant across age groups. Mean measurement error was within 1 dB. These errors increase with increasing SRTTn.

Conclusions: This study shows the implementation and results from a functional hearing screening test by telephone. The test can be done in about 3 minutes, 30 sec, including introductory text, explanation of the test procedure, test result, and recommendation for audiological evaluation. The high number of callers implies that the test is probably fulfilling the need for a functional hearing screening test and has enhanced public awareness about hearing loss.