These inventions are useful for hear-through headsets, helmets and earplugs used in noisy environments. People often need hearing protection in loud environments. However, effective hearing protection diminishes situation awareness. Hear-through systems provide the user with acoustic signals from the environment, but at safe levels. Ideally, hear-through hearing protection systems are acoustically transparent. That is, the user essentially hears no difference wearing the system except when the ambient noise is damaging, in which case, the system provides gain reduction, compression and clipping techniques to prevent damaging exposure.
The patents presented here are for ear simulators that mimic the acoustic response of a human ear, a channel switching system that routes left and right signals for improved speech intelligibility during face-to-face communications, an earcup design, a microphone protection device and a system combined with active noise control that modifies the hear-through and ANC parameters based on ambient noise.
In addition to the patents presented here, RTH has developed trade secrets relating to the processing of audio signals including automatic gain control, compression and clipping to achieve the best user experience.
Click on the images to see the title page of patents and on the links below to download full patents.
Talk-through listening device channel switching
This invention is useful for talk/hear-through headsets, helmets and earplug used in noisy environments. A headset example follows: Under typical conditions, the headset would be providing hearing attenuation; however, sometimes the user would like to hear the speech of another person during face-to-face communications. The user, or talker, presses a button to engage speech routing and signal processing. When speaking into the left earcup and pressing the left button, the microphone signal from the left earcup is routed to the left and right earcups, and vice versa. In this way, the speech-to-noise ratio is increased in the ear facing away from the speaker.
Ear defender with concha simulator
This acoustic device is used to simulate the response of the human ear with microphone. The device helps create the directivity and response characteristics of a human ear and may be used on ear defenders. When used in a hear-through system helps to restore natural sounding monitoring of ambient environment.
Microphone environmental protection device
This pending patent describes a device for protecting microphones from environmental conditions that is particularly suited for talk/hear-through systems. Foreign patent applications have been filed and are pending.