Think-A-Move, Ltd.

Think-A-Move's patented in-ear microphone earpiece and proprietary noise-canceling algorithms allow users to communicate under the loudest of conditions. Whether it be for military use in warzones with battlefield noise, a crowded rock concert, or everyday cell phone use on a city street, the TAM system eliminates ambient noise and allows users to hear in conditions exceeding 95 dB. No competitor even comes close.

Audio Demonstrations

Audio tracks 1-3 demonstrate TAM's speech equalization and noise cancellation algorithms. Tracks 4 and 5 demonstrate TAM's echo cancellation algorithm. All the original recordings were made using TAM's proprietary earpiece that contains internal and external microphones and an internal speaker.

Tracks 1-3
The original recording (Track 1) was made with the user wearing TAM's proprietary earpiece, and 85 dB of babble noise played in the background.

Tracks 4 and 5
The original recording (Track 4) was made with a user wearing TAM's proprietary earpiece, and another person's voice being played through the earpiece speaker. The speaker signal leaks back into the microphone producing the echo. Track 5 is the original recording processed for echo cancellation.

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1. Raw recording (RR) from the external mic.

2. Internal mic recording processed for speech equalization (SE).

3. Internal mic recording processed for SE and ambient noise cancellation (ANC).

4. RR from internal mic with echo.

5. Recording with echo (Track 4) processed for echo cancellation.

Two-way Voice Communications
The TAM system provides full duplex transmission, meaning both sides can communicate simultaneously. Currently, other in-ear communications devices allow for half duplex, where only one side can communicate at a time. Handheld transceivers (i.e. walkie-talkies) are an example of half duplex.

The TAM system for communications features an in-ear microphone that picks up a user's speech, and an internal speaker to relay speech from the other end. The in-ear microphone offers two major benefits:

However, this design could potentially pose two problems:

Solution
Think-A-Move's engineers developed specialized algorithms that take advantage of the benefits of using an internal microphone, while solving the problems associated with it. These algorithms include Acoustic Echo Cancellation, Ambient Noise Cancellation and Speech High-Band Reclamation.

Acoustic Echo Cancellation
As stated above, the close proximity of the speaker and the microphone cause leakage from the speaker into the microphone and produces an echo. The Acoustic Echo Cancellation (AEC) module solves this problem by eliminating the echo, using an algorithm known as an Adaptive Filter. However, AEC is highly complex, and in addition to the Adaptive Filter, AEC contains four additional components:

Ambient Noise Cancellation (ANC)
The ear-tip in TAM's earpiece provides substantial passive ambient noise cancellation by sealing off the ear canal from outside noise. However, in a high-noise environment, ambient noise can leak into the ear canal and affect the quality of the voice picked up by the internal microphone.

To combat this problem, Think-A-Move's engineers designed a function that eliminates ambient noise. The ANC uses a unique two-step noise cancellation method, which reduces noise separately for speech and non-speech frames, employing two different adaptive algorithms. A further reduction in leaked ambient noise results.

Speech High-band Reclamation (SHR)
User speech, captured in the ear canal, is essentially the result of bone conduction. The muscles and tissues covering the skull have an extreme low pass filtering effect on this signal, causing the low frequencies of speech to be amplified, intermediate frequencies to be dampened, and higher frequencies to be greatly attenuated. In addition, the microphone, unlike an external unit, might not incorporate the high pass filtering effect due to the radiation load in the mouth. These factors together make the speech picked up by the internal microphone sound muffled.

To counter these effects, the TAM system provides a speech high-band reclamation function, reclaiming frequencies and making voice sound natural.