It is essential but quite challenging to alleviate speech information loss and distortion while developing the speech processing algorithms in hearing aids. Recently, many speech enhancement methods based on deep learning are proven effective. However, most of the algorithms fail to achieve real-time processing, which is significant for hearing aids, especially for a smartphone-centered binaural hearing aid system. A supervised speech enhancement method based on an RNN structure is proposed to address the real-time problem. The problem is explored as a resource-constrained speech intelligibility improvement problem with the target of improving speech intelligibility at low SNR situations. Both the objective and subjective experimental results, using the standard evaluation metrics and the experiments on volunteers, respectively, have verified the superiority of the proposed method.

Hearing loss is an irreversible damage. Patients with hearing loss usually use hearing aids or cochlear implants for hearing compensation. Hearing test is used to detect hearing-loss degree in different frequency bands for both ears or for the single ear with hearing loss. The conventional hearing test method requires an audiologist to conduct the test process, which causes a burden for the patient in respect of cost and time. This paper describes a new smartphone-based audiometry method for the hearing self-assessment using hearing aids as the audio sources, a smartphone as the user-interface and controller. The hearing aids are controlled by the smartphone through low-power wireless communication link. The stimulus audio signal with the feature of sweeping amplitude out of the hearing aids is generated by an innovative "coarse-to-fine focus" algorithm, which reduces test time and improves test accuracy as well. The proposed method is verified by a demo smartphone-based hearing self-assessment (SHSA) system, which consists of hearing aid hardware, user-interface application, and stimuli generating algorithm. The objective measurement of the demo system verifies the precision of the sound level within a variation less than 0.5 dB HL for all 6 frequency bands. The subjective test with 20 samples with different levels of hearing loss in a sound-proof booth indicates that the SHSA system has an average difference of less than 6 dB HL for different hearing-loss severity, and is capable of saving more than 50% hearing test time on average compared to the conventional hearing test.

A thermal THz detector based on commercial CMOS technology working in room temperature is proposed. The THz electromagnetic wave is first selectively absorbed by an on-chip λ/4 dipole antenna realized in the metallization layer. The absorbed wave energy is then converted to Joule heat energy via a polysilicon resistor. The heat-generated temperature rise is finally detected by a proportional to absolute temperature sensor. The theoretical analysis and physical modeling of the detector including the mechanism of the electromagnetic energy absorption, the thermal conversion, and the electrical circuit response, are presented. The detectors at three typical THz frequencies of 1, 2.9, and 28.3 THz are designed in standard 0.18-μm CMOS technology and post-simulated to illustrate the detector's frequency-selective capability in the whole THz range. The simulated detector's voltage responsivity is 18.0 V/W at 1 THz, 18.9 V/W at 2.9 THz, and 18.6 V/W at 28.3 THz, respectively. The noise equivalent power is 1.7 μW/√Hz at the three frequencies.

This brief presents a noninvasive energy-efficient frequency-modulated ultra-wideband (FM-UWB) transceiver. 8-frequency-shift-keying (FSK) subcarrier modulation is utilized to enhance the data rate with a slight increment of hardware complexity compared to the conventional 2-FSK FM-UWB system. The transmitter employs a fast settling PLL with a pretuned relaxation VCO for 8-FSK subcarrier modulation. The transmitted signal by an FLL-assisted ring VCO followed by a single-stage class AB power amplifier meets the FCC spectrum mask. The regenerative receiver employs a wideband LNA with a stacked structure to save power. Two 4th-order Butterworth bandpass filters and envelope detectors convert the FM signal to an AM signal with good linearity. The 3.5-4 GHz 750-kb/s transceiver implemented in 65-nm CMOS consumes 5 mW from a 1-V supply, achieving an energy efficiency of 6.7 nJ/bit.

This paper presents a new structure for hearing aids. Normally, the power consumption and user experience are contradictory. The proposed hearing aid structure mainly consists of three parts: the earpieces, the mobile computing platform, and the real-time speech-enhancement application. It can run complex algorithms without carrying out heavy calculations on the processors in the hearing aid. Thus, the binaural algorithm is utilized without being limited by complexity and power consumption to improve the user experience. Moreover, the speech-enhancement algorithm can be updated much more easily than in traditional built-in digital signal process hearing aids. A good level of user experience is achieved by combining the hearing aid and mobile computing platform with a 400-MHz transceiver; furthermore, the 400-MHz transceiver can reduce path loss around the body. The concept verification process showed that the overall usage of the central processing unit in the smartphone is around 16%, the signal-to-noise ratios show at least a 30% improvement in some environments, and the whole system delay is 8.8 ms. The presented objective and subjective results show significant improvements regarding user experience and usability brought about by the proposed structure.