The lowly dial tone. We are all used to hearing it for most of our lives. When you pick up the telephone receiver and hold it to your ear the familiar sound of the dial tone resonates clearly. In fact, those of you who have traveled abroad have probably noticed that our old phone dial tone is not the same in Western Europe. Once back in the United States you will realize how much you missed the classic rotary phone dial tone.
History of the Rotary Phone Dialtone
The dial tone is actually a combination of two different tones, or frequencies. These two tones actually beat together – technically called modulate – and do so very quickly. They are in the range of 350 Hz to 450Hz. The reason they sound so familiar is because other countries often use a single tone which has a completely different sound to it.
Prior to the advent of automatic dialing, telephone operators used to complete the calls that were placed from our old rotary dial desk phone or rotary dial wall phone. Customers who’d been used to hearing the voice of the operator when they picked up the phone were confused by the silence of the new automated switching systems, so the telephone companies added the dial tone so that the caller new they were connected and could make a telephone call. The telephone company referred to this dial tone as “comfort noise”. It became known as the dial tone and that’s what we still call it today.
Rotary Dial Phone Dial Tone
In case you forgot what the old phone dial tone sounds like, follow this link to Listen to the Dial Tone!
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