Is the sensitivity of the intercom as high as possible?

The higher the sensitivity, the better

Some people often boast that the higher the sensitivity, the better. However, it is not always the case that "the more sensitive, the better". For example, it is not applicable to listening to high-power radio stations of hundreds of kilowatts (KW). A 0.1uV (microvolt) radio may not be easier to receive broadcasts than a 0.5uV model. International tests often use intelligible to express it. For example, an experienced CW operator can interpret a CW signal that is only 1.4 times (2dB) higher than the background noise, but it is higher for voice signals. It is also a bit difficult to broadcast a signal that is 4 times (12dB) higher than the background noise. If the difference is increased to 10 times (20dB), it can be easily listened to, and the difference is increased to 20 times (26dB) without any effort to listen to clear and unobstructed signals.
When listening to the radio, the receiving antenna not only senses the broadcast signal, but also receives a lot of background noise. These different forms of noise are divided into 3 types:
1. Cosmic noise (galactic noise): The sun is the largest source, Reception below 100MHz will be affected.
2. Atmosphere noise: Since there are nearly 30,000 thunderstorms every day, the lightning will increase the background noise, especially in tropical areas, which is more seriously affected. This is one of the reasons why the tropical frequency band (2.3-6.3MHz) is not easy to receive.
3. Man-made noise: This is all the household appliances you use when receiving the letter, such as washing machines, desk lamps, drilling machines, car engines, even if you live in the suburbs, the power lines passing overhead are also a super wideband noise transmitter.
The background noise caused by all electrical interference is far higher than 10 times the atmospheric noise. The following data on the intensity of cosmic noise can be inferred from how serious the man-made noise is.

Suppose you want to listen to the 7.2MHz (7200kHz) broadcast signal, the intensity is just 0.90uV when it reaches the radio, obviously you can't hear it, unless the radio signal is increased to 3.16 times (10dB) or more to overcome the cosmic noise, and this does not take the factors of the receiver into consideration! A more sensitive radio only gets a stronger signal index, but compared with a less sensitive walkie-talkie, the discernibility (signal/noise ratio) of the two is completely unchanged!
Therefore, using a wideband amplifier to amplify the signal does not help the radio, it just makes the signal index higher, but it will make the reception worse, and this does not add the factor of artificial noise, assuming that the internal circuit of the radio does not generate noise.
Based on the above explanation. We have strong reasons to recommend not looking for a sensitive radio, but to look at other indicators, such as selectivity, cross-modulation, inter-modulation and other numbers.
After reading this article, Do you think it would be better to choose a radio with a sensitivity of 0.1uV rather than a radio with a sensitivity of 0.5uV?