G10K 11/22 for conducting sound through hollow pipes, e.g. speaking tubes
Introduced: January 1980
Full Title
Full titles differ between systems:
Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general > Methods or devices for transmitting, conducting or directing sound > for conducting sound through hollow pipes, e.g. speaking tubes
Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general > Methods or devices for transmitting, conducting or directing sound (G10K11/02, G10K11/36 take precedence) > for conducting sound through hollow pipes, e.g. speaking tubes
No child classifications to compare. This is a leaf node in both IPC and CPC.