Final answer:
To maintain a clear and audible tone, project your voice beyond the person or telephone, considering the ambient noise level. Sound intensity decreases with distance, so it's recommended to project your voice at a level higher than the ambient noise, around 65-75 dB.
Step-by-step explanation:
In order to maintain a clear and audible tone, you should project your voice beyond the person or telephone by a specific distance. This distance depends on the intensity and distance at which you are projecting the sound.
One way to measure the intensity of sound is using decibels. The threshold of human hearing is around 0 dB, and as the distance from the source increases, the sound intensity decreases. At a distance of about 1 meter from the speaker, the sound intensity is generally around 60-65 dB.
To maintain a clear and audible tone, it is recommended to project your voice at a level higher than the ambient noise. In a quiet room, projecting your voice at around 65-75 dB should be sufficient.