"In the face of thousands of listeners in the square, it is not easy for the orator to clearly convey every word to the ears of the citizens, not to mention that there are large groups of opposition listeners below, these opposition parties will often organize under the leadership of the party leader, collectively cheer for the speakers, make noisy noises to interrupt the speech, interfere with the other party's train of thought, no matter how loud the speaker's voice is, it cannot compete with the noise of the crowd, so a tool is needed to raise the volume of the speaker to suppress the noise, and 'amplification' came into being."

Roland took a sip of Beacon Hill's specialty refreshing tea to moisten his throat, and continued: "Although the 'amplification technique' is only a very simple 0-ring trick, it brings great convenience to public life, because most of the street speakers themselves do not know how to cast spells, in order to facilitate the expansion of the volume, some smart people have thought of constating this spell on an iron sheet or wooden wide-mouth horn, thus creating a simple magic guide with amplification function - amplification horn, a person who holds a loudspeaker to speak on the street, also known as 'making a broadcast',' Thus was born, and today, the megaphone is no longer the exclusive tool of politicians and social activists, and the concept of 'radio' is deeply rooted in the hearts of people who are no longer the exclusive tool of politicians and social activists, and the vendors who sell fruit in the market, the shops that advertise discounts, and the school principals who lecture to the students. ”

"It's very well interpreted, and I'd like to hear you talk about the 'hotel-style' radio model." Andrei encouraged.

Roland took another sip of tea. Over the years, he was accustomed to drinking fermented black tea, the "national drink" of the Far Easterners, while Beacon Hill was popular with an unfermented, green-colored drink that was closer to the "green tea" of the earth, with a light and refreshing taste and a variety of refreshing herbs added to help arcane spellcasters meditate. Roland also drank more green tea than black tea when he was on earth, and the herbal tea from Beacon Hill brought him a sense of homesickness, and he secretly decided to buy more "Zoche green tea" to bring back to Krasbourg to give to relatives and friends.

"There is an insurmountable shortcoming of 'square radio' based on 'amplification': the speaker cannot sift through the audience, for example, I only want to say a few words to the male compatriots in the square, but the sound from the loudspeaker will also reach the ears of the female compatriots, which is embarrassing...... On the other hand, listeners can't refuse to listen to the radio, for example, I live near the municipal square, I am distracted by the radio every day, I can't wait to plug my ears, in order to overcome the above shortcomings, people need a more targeted, more privacy-oriented radio model, this model was first born in the hotel industry, hotel guests will always need room service, and do not want to go downstairs to find a waiter, urgently need a convenient customer service system. ”

"In order to meet the above needs, the trap warlocks first invented a ' 'Pull the bell', install a thin line between the room and the service desk, one end is fixed on the side of the bed in the guest room, the other end is tied to the bell, the guest pulls the rope in his bedroom, the bell at the service desk downstairs will give applause, the waiter will see which guest needs service according to the room number marked on the bell, will arrive as soon as possible, this system is still used in today's small country hotels, but the luxury hotels in big cities have abandoned it, because the bell alone can not fully convey the needs of the guests. ”

Speaking of which, Roland made a figurative analogy.

"For example, I live on the third floor of the hotel and want a pot of boiling water, so I ring the bell, and the waiter climbs up to the third floor and knocks on my door, and after asking me what I need, I have to go downstairs to carry the kettle, which undoubtedly increases the waiter's workload, reduces the efficiency of service, and also brings me interference - I have to open the door twice and wait twice as long to drink boiling water."

"For this reason, the 'bell pulling system' needs to be modified so that it can convey more accurate information." Andrei said with a smile.

"That's right, it's no longer possible to find out who invented the improved system, his method is to change the fishing line connecting the guest room and the service desk to a thumb-thin copper pipe, as a sound channel, the guest can shout through the horn at one end of the pipe, through the amplification effect of 'amplification', clearly transmitted to the downstairs service desk, so that the waiter knows what kind of service the guest needs, this is the most primitive 'hotel broadcasting' system." Roland recalls the history of Vares' broadcasting technology, and goes on to say, "As time went on, it became clear that the aforementioned sound transmission system was not perfect, for example, when the tenant was talking to someone in the bedroom, these conversations that he did not want to be heard by outsiders would also be transmitted to the ears of the waiter through the loudspeaker, which caused a lot of trouble, so a clever mage improved the 'amplification' and invented another great 0-ring spell" Communication', this spell can make the words pass to the ears of a specific target, and the people around them can't even hear a word, this technology has greatly improved the hotel broadcasting system, and soon someone found that 'communication' can transmit sound signals for multiple targets at the same time, this feature was immediately applied to commercial propaganda by the witty hotel owner, in the hotel, a special broadcast room was opened, and the broadcast horn of the constant 'communication' was placed, and at the same time in the restaurant, bar, smoking room, tea room, chess and card room, Swimming pools and other facilities that provide entertainment and leisure activities are equipped with loudspeakers that can receive announcements, so that when the hotel waiters introduce the restaurant's specialties and famous wines in the broadcast studio, the sound will reach the ears of the guests of the leisure facilities in each place. Later, for safety reasons, high-end hotels generally installed an emergency broadcast system, when the hotel fire, the alarm can be sounded in the broadcast room, and through the broadcast network to all guest rooms, wake up the sleeping guests, so far' The hotel-style PA system was perfected and quickly spread to other industries, such as most of the systems installed on ships and airships, as well as in our government and bank buildings in Krasbourg, so that people could communicate with their colleagues upstairs and downstairs while sitting in their offices, and officials and bosses could use the system to communicate instructions to multiple subordinates in different offices at once, which was very convenient. ”

When Roland finished his ten-minute narration, André used his "mage's hand" to pick up the teapot and pour him a cup of fragrant herbal tea.

"You have a deep and detailed understanding of Magic Radio, so in your opinion, what are the technical obstacles to upgrading the existing broadcast model to a national broadcast network?"