Public speaking coaches, often referred to as oratory mentors or speech trainers, are professionals who equip individuals with the necessary tools to deliver compelling presentations and speeches. With a foundation in communication theory, human psychology, and performance techniques, these coaches guide their clients towards improved articulation, increased confidence, and effective storytelling.

To understand the necessity and the influence of public speaking coaches, it is essential to first appreciate the value of robust communication skills. Communication is the bedrock of human interaction and is a key determinant in one's personal, academic, and professional success. It is the fundamental medium through which we share knowledge, express ideas, and build relationships. In a world that is increasingly interconnected, the ability to communicate effectively is a prized asset.

Public speaking coaches exist within this context. They assist their clients in overcoming the fear of public speaking, termed 'glossophobia', which is surprisingly common with studies indicating that it affects about 75% of the population. The scope of their work is not limited to tackling glossophobia; they also help individuals enhance their existing skills for more persuasive and impactful verbal expressions.

These coaches are proficient in various communication models such as the transactional model, which postulates that communication is a reciprocal process that involves the exchange of messages between the sender and the receiver. This understanding helps them to address the dynamic nature of public speaking where the speaker must adapt their message based on the audience's feedback.

In the journey towards becoming an effective orator, the speaker will encounter numerous trade-offs. For example, the use of visual aids can offer clarity to a presentation but can also become a distraction if not used appropriately. Public speaking coaches provide guidance on how to navigate these trade-offs to ensure the overall effectiveness of the presentation.

These coaches employ a plethora of techniques to improve public speaking skills, ranging from traditional methods such as practice speeches and feedback sessions to innovative technologies like virtual reality. Through the latter, clients can simulate various speaking environments and receive real-time feedback on their performance.

The impact of public speaking coaches is not limited to enhancing the speaker's performance on stage. It extends to improve the speaker's critical thinking skills, emotional intelligence, and leadership abilities. By focusing on aspects like strategic use of language and body language, understanding the audience's psyche, and improving self-confidence, these coaches ensure a holistic growth of the speaker.

However, one must remember that the effectiveness of a public speaking coach is contingent on the individual's willingness to learn and adapt. As the old adage goes, "You can lead a horse to water, but you can't make it drink," the coach can provide the tools and techniques, but it is ultimately the speaker's responsibility to implement them.

In conclusion, public speaking coaches play an instrumental role in refining an individual’s communication skills, thereby enabling them to express their ideas more convincingly and confidently. Whether you aspire to be a professional speaker, or you simply wish to improve your day-to-day communication, engaging a public speaking coach can be a strategic move towards achieving your goals. Like a master craftsman honing a raw stone into a precious gem, a skilled public speaking coach can help you polish your natural ability to communicate into a powerful skill that can open doors and create opportunities.