Abstract
The lateralization of tinnitus on the cranium was measured by a directional hearing device, which can generate binaural time or intensity differences for various sound sources. Tracings of sound locomotion are recorded as sawteeth-like waves by repetition of the dial operation in the right and left directions.
First, the central and lateral sound images on the cranium were measured by method of adjustment for subjects with normal hearing. The range of the values was determined after three measurements per day for three days. The regions of these locations of sound impression were in close agreement, and 67% of 20 normal control subjects showed stable results.
Next, 30 subjects with normal hearing ability and monaural tinnitus were tested. The location of tinnitus on the cranium was determined after localization of the sound impression in the central and lateral positions by the method described above. The results were as follows: in 53% of the subjects the results were stable; 46% showed agreement between the positions of tinnitus and the lateral side, and 27% showed a more medial impression of tinnitus than the lateral position.
This method has no restrictions as a clinical test. The fact that the position of tinnitus may disagree with the lateral impression on the cranium was clarified by these experiments.
