Noise attenuating stethoscope
Noise cancellation apparatus
Noise reduction spoiler for a damper
Noiseless air flow device and method
Non-electronic hearing aid
Non-roll foam eartip
Nonlinear ear protecting device
Nonlinear passive acoustic filtering
Open-air type earphone
Oval dome type speaker
Passive personal vocal monitor
Passive sound gathering apparatus
Patient-to-transducer interface device
Peripherally reinforced laminated loudspeaker diaphragm
Permeable aerodam to reduce wind noise
Personal protective devices having an energy activated material
Piston loudspeaker
Piston-diaphragm speaker
Pivoted loudspeaker enclosure with visual indicator of optimum l
Planar sound reproducing speaker system