Why doesn t touch tone work?

Touch-tone dialing refers to the system used on most landline and mobile phones to dial a phone number. It uses distinct combinations of dual-tone multi-frequency (DTMF) signals to represent the digits 0 through 9, along with * and #. When a user presses a key on the phone keypad, a unique tone is generated based on the frequency of two specific tones, which is then transmitted down the phone line. At the other end, the central office or mobile network recognizes these tones and converts them into the corresponding digit to connect the call.

The touch-tone system was developed by Bell Labs and AT&T in the 1960s as an advancement from rotary dialing, allowing calls to be connected much faster. It became the standard system across most phone networks by the 1980s. (https://memorial.bellsystem.com/belllabs.html)

Technical Limitations

One reason why touch tone may not work in some cases is technical limitations in phone systems. Originally, telephone systems were designed for pulse dialing using rotary phones. As this journal article explains, adapting these analog systems to support touch tone dialing required extensive upgrades to equipment and infrastructure, which was quite costly.

Touch tone phones generate audible tones to represent the different digits, using a technology called dual-tone multi-frequency (DTMF) signaling. Older electromechanical switching systems were not designed to recognize these tones, but rather used the timed electrical pulses from a rotary phone to determine the digits dialed. Upgrading all central office switches and exchange equipment to support DTMF required major financial investment from telephone companies.

Incompatible Phone Systems

Many older analog phone systems still in use simply cannot process touch tones. These systems rely on pulse dialing, an older technology that predates touch tone dialing. Upgrading these legacy systems to support touch tone dialing would require expensive hardware upgrades that most businesses and individuals have not invested in.

As explained in this Verizon community forum post, “Old Touch Tone Phone Can’t Make Outgoing Call”, older touch tone phones often will not work properly on modern phone systems that expect tone dialing. Without hardware upgrades to support tone dialing, calls may fail even if a dial tone is present.

Additionally, some antique rotary phones converted to touch tone dialing can exhibit problems processing touch tones, as described in this vintage phone forum post titled “1975 W/E 2500 touch tone, not breaking dial tone **pics …”. So even “upgraded” vintage phones can struggle with inconsistent touch tone operation.

Cost of Upgrading

A key barrier preventing wider adoption of touch tone dialing is the high cost for companies and organizations to upgrade their phone systems. According to an article on A.T.&T. pricing in 1983, a standard touch tone phone cost over double that of a rotary dial phone ($41.95 vs $19.95) (NY Times). Upgrading an entire organization’s phone system requires purchasing new touch tone-compatible phones for all employees as well as installing supporting infrastructure. This significant upfront investment serves as a deterrent, especially since organizations do not directly benefit financially from upgrading.

Lack of Financial Incentive

A major reason touch tone dialing is not universally adopted is that there is little financial incentive for telephone companies and governments to make the significant investment in upgrading equipment and infrastructure.

Upgrading telephone exchanges to support DTMF dialing requires replacing mechanical switches with digital ones, which can be very costly for companies. The touch tone system also requires more bandwidth and advanced equipment on the customer side, which most homes and businesses have little incentive to purchase without being required to.

Since many systems still rely on outdated pulse dialing, there is not enough consumer demand and financial return to motivate a complete switchover of the telecommunications infrastructure. Companies focus spending on services with clearer paths to profitability.

Habit and Inertia

Many people used to using rotary dial phones have been reluctant to transition to touch tone dialing. As recently as 2016, many teenagers were still unfamiliar with how to use a rotary dial phone, according to this Quora post. However, rotary dial phones were the norm for several decades in the 20th century. The rotary dial was invented in the late 1800s and did not begin to be phased out until touch tone service was introduced in the 1960s. According to Wikipedia, rotary dial phones remained commonplace in the US up through the 1980s and into the early 1990s.

For people who used rotary dial phones for their whole lives up until the 1990s, learning a new way to dial could feel unnecessary or inconvenient. Sticking with what feels familiar can be preferable to investing effort in learning something new. So for many holdouts still using rotary phones today, touch tone may simply never catch on due to habit or resistance to change after decades of doing it “the old-fashioned way.”

Accessibility Issues

Touch tones can present challenges for people with disabilities, especially those who are visually impaired. As this source explains, “People with speech impairments, mobility impairments, and visual impairments may have difficulty with mainstream landline and wireless telephone interfaces.”

For those with visual impairments, touch tones require pressing keys on a dial pad that they cannot visually confirm. This means they have to rely solely on tactile or audio feedback to know which key was pressed. The lack of accessible markings or tactile differentiators on most dial pads further aggravates this issue. As a result, navigating phone menus or inputting data via touch tones can prove difficult for the visually impaired.

Security Concerns

When touch tone phones were first introduced, there were concerns that they were less secure than rotary phones. The tones generated by touch tone phones can be recorded using basic audio equipment and decoded back into phone numbers (Rotary Phones vs Pushbutton). With a rotary phone, the clicks were mechanically generated within the phone itself, making it harder for an external device to intercept and decode them.

This led some government agencies and corporations to avoid upgrading to touch tone systems. The pulses produced by rotary dials were considered more difficult to tap and decode (Why Did Telephones Use a Rotary Dial). Over time, as encryption technologies improved on phone systems, the security concerns with touch tone systems faded.

However, even today some sources argue rotary dial systems provide greater inherent security. The analog clicks of a rotary phone remain challenging to intercept and convert digitally. Whereas the distinct tones of touch tone phones can potentially be identified and decoded by audio analysis software.

Cultural Perceptions

Touch tone, or touch-tone service, has sometimes been perceived as cold or impersonal as the user is interacting with pre-recorded tones through the keypad rather than an actual person. The lack of emotional connection or empathy that touch tones convey may elicit negative cultural associations.

Some cultures place a high value on direct personal interactions, so communicating through automated tones can seem detached. However these cultural perceptions are changing as digital interactions become more common.

Conclusion

In summary, there are several key reasons why touch tone dialing has failed to fully replace rotary phones after over 50 years:

• Technical limitations – Many older phone systems are not compatible with touch tone, and upgrading can be prohibitively expensive.
• Lack of financial incentive – Phone companies often don’t see enough potential revenue to justify upgrading their systems.
• Habit and inertia – Many people continue using rotary phones out of habit, custom or preference.
• Accessibility issues – Rotary phones are easier to use for some people with disabilities.
• Cultural perceptions – In some regions, rotary phones are seen as charming, vintage or elegant.

While the majority of phone users utilize touch tone dialing, a small but meaningful number continue to use rotary phones to this day. Complete replacement is unlikely given the remaining technical and cultural barriers.