| 381 / | HD | ELECTRICAL AUDIO SIGNAL PROCESSING SYSTEMS AND DEVICES |
| FOR 127 | DF | HEARING AIDS, ELECTRICAL (381/68) {15} |
| FOR 152 | | .~ Electromagnetic (e.g., dynamic) (381/192) {5} |
| FOR 153 | DD | .~.~> Having feature of edge-supported diaphragm (381/193) |
| FOR 154 | DD | .~.~> Movable voice coil (381/194) {3} |
| FOR 158 | DD | .~.~> Including adjustment mechanism (381/198) |
| FOR 159 | DD | .~.~> Magnetic circuit or core structure (381/199) {2} |
| FOR 162 | DD | .~.~> Specified diaphragm shape or structure (381/202) {2} |