###### Abstract
[19] present a solution for echo cancellation. This innovative approach, a blend of hardware and a deep learning algorithm, leverages the DPRNN (Dual-Path Recurrent Neural Network) to improve signal quality through a 50 mm aluminum metal barrier. The potential impact of this solution is significant, with a 20 dB increase. Temperature variations are one of the main factors that affect the propagation of ultrasonic acoustic waves [7; 20; 21]. Hence, characterizing and investigating the efficiency of ultrasonic communication systems under the influence of such factors is of great importance to developing the ultrasonic telemetry field. Recent works have disclosed ultrasonic wave-based communication systems that were proven to be feasible at different temperature conditions (e.g., [22; 23; 24; 25]). [PERSON] et al. (2022) [22] present the design of a communication system based on the propagation of acoustic waves in an urban water distribution pipeline. The frequency response of the system is modeled in a black-box approach, and the derived model is used to simulate a complete communication system. The authors show that a good choice of modulation parameters is critical in dealing with problems like frequency selectivity and multipath propagation. Their communication tests demonstrated successful transmission while the environmental temperature varied from 5 to 17 \({}^{\circ}\)C. However, such a temperature range lies in an interval that reflects natural ecological conditions. Other works by [PERSON] et al. [23] investigated the efficiency of ultrasonic communication systems under more extreme conditions. They investigated the influence of temperature on communication systems based on ultrasonic guided waves. A steel pipe was instrumented with LiNbO3 transducers and a temperature controller to evaluate the communication system, ranging from room temperature to 150 \({}^{\circ}\)C. The signal-to-noise error (SNR) and the bit error rate (BER) were the metrics for estimating communication performance. According to the authors in [23], the ultrasonic communication system is feasible at least to 150 \({}^{\circ}\)C, reaching an error-free bit rate of 10 kbps. [PERSON] et al. [24] investigated the feasibility of using a nuclear-grade stainless-steel pipe as a channel to transmit image data with ultrasonic elastic waves. Heating tapes, temperature controllers, and thermal insulation were installed on a laboratory-scale replica of a stainless-steel pipe found in a chemical volume control system to simulate nuclear facility conditions at high temperatures. An amplitude shift keying protocol combined with a root-raised-cosine filter enhanced data transmission compared to square pulse encoding. The results indicated that a 90 kB image could be transmitted with a 10 kbps bit rate and BER of \(10^{-3}\) across a six-foot pipe at 230 \({}^{\circ}\)C.  
Another factor that affects the propagation of ultrasonic waves is the action of mechanical stresses in the acoustic channel. The acoustoelastic effect, i.e., the influence of the stress field on the propagation of elastic waves in elastic media, has been thoroughly investigated for many decades and proven to be an efficient stress measurement technique [26; 27; 28]. However, it may be detrimental in ultrasonic telemetry by interfering with the impedance of parts that make up the acoustic channel. However, most works investigating the influence of mechanical stress on ultrasonic waves refer to non-destructive testing (NDT) or structural health monitoring (SHM) applications. Regarding the latter, the interest in employing active, piezoceramic pairs of transmitter-receivers to detect faults (continuously and in real-time) in structures dates from the early 1990s, and the field of SHM has grown considerably since then. In these applications, transmitters and receivers are permanently attached to the monitored structure, and, therefore, the influence of stress/strain variations in the ultrasonic channel may be more pervasive than in NDT practice.