MAGIC (Multiple-choice Auditory Graphic Interactive Check)
MAGIC (Multiple-choice Auditory Graphic Interactive Check) is a new image-based, self-controlled test for determining pure-tone thresholds in playful way.
Findings concerning feasibility and reliability of the test in children are described in a multi-centre study conducted at Department for Communication Disorders, ENT-Department of the University of Mainz Medical School´s hospital (Germany), at the ENT clinic of Klinikum rechts der Isar, Technische Universität München (Germany), and at Cyprus Audiology Center Nicosia (Cyprus) (Schirkonyer et al. @ DGPP)
Measurements were conducted in 108 children aged between 3;6-11;11 years at the frequencies 0.5, 1, 2, 4 kHz (n = 82) and additionally at 0.25, 3, 6, 8 kHz (n = 26) using Sentiero (PATH medical). Different animals represented different frequencies (bear 500 Hz, elephant 1 kHz, etc.). Each animal was present in three variants: Neutral to start the sound presentation, happy/healthy and sad/sick for indicating the two conditions ‘heard’ and ‘not heard’.
Before measurement a story was told such that the child was instructed that healthy animals will make sounds and sick animals are not able to. By telling this story (download pdf), the child is put into to role of the doctor! Consequently any potential fear is taken away from the child, because it’s not the child to be examined, the child is the examiner!
The test procedure prog ress is visualized by a shelf or waiting room, from which the current test animal have to be selected. The test is controlled by the child itself via touch screen. This includes sound presentation as well as input if the sound was heard (healthy animal) or not (sick animal). The examiner is supposed to supervise the measurement and assisted the child with the entry of the result – when indicated. The examiner could also intervene in the measurement procedure at any time or do a retest at any frequency whenever necessary.
Additionally, hearing threshold estimation by means of DPOAE I/O functions (see Relation between DPOAEs and behavioural pure-tone thresholds p.12) were performed in 36 children from the collective. DPOAE I/O functions were recorded at frequencies f2 = 1, 1.5, 2, 3, 4 and 6 kHz with primary tone levels (L2) in the range from 10 to 65 dB SPL and threshold were estimated by linear regression analysis. Primary tone levels L1 and L2 were set according to the “scissors paradigm”. The frequency ratio f2/f1 was 1.2.
For comparison, play-audiometry pure tone thresholds were determined at the corresponding frequencies.
There was a highly significant (p<0.001) correlation between image-based (MAGIC) and play-audiometry (PTA) thresholds. The correlation coefficient (r) (n=1247) was 0.73. The histogram of the difference between image-based and play-audiometry thresholds showed normal distribution. Mean and standard deviation of the differences amounted to -1.5 dB and 9.6 dB, respectively. Test time per frequency (one ear) was on average about 30s, ranging from 14s to 91s. Test time decreased with increasing age.