More and more consumers are letting their fingers do the talking, according to a recent study conducted by the CTIA-The Wireless Association. The group’s bi-annual report closely tracks trends in wireless subscribership, revenue, capital investment and infrastructure. Among the many results showing the wireless industry’s growth, there were dramatic increases in wireless data usage, smartphone adoption, capital expenditures and SMS and MMS traffic.

Yet there have also been some noteworthy drops in usage. The survey, which follows data submitted by carriers through June 2010, found that the length of the average U.S. mobile call was just 1.67 minutes in the first half of 2010, only the second time that the average wireless chat fell below two minutes since 1993, when the CTIA began following trends in the wireless industry. What’s more, the average local monthly bill fell by 4.2 percent to $47.47 over the past year.

That’s not to suggest, however, that wireless subscribers are dwindling in numbers. Rather, wireless subscriber connections rose to 292.8 million, an increase of roughly 16 million since June 2009, representing a penetration rate of 93 percent. These subscribers used 2.26 trillion minutes (up by 19 billion minutes), 1.8 trillion SMS messages (up by 33 percent) and 56.3 billion MMS messages (an increase of 187 percent).

Smartphones and wireless-enabled PDAs also grew significantly over the past year, increasing from 40.7 million in July 2009 to 61.2 million in June 2010. This brings the total number of data-capable devices on carriers’ networks to 264.5 million. Wireless carriers reported handling 161.5 billion megabytes of data in the six months ending in June 2010, up 49.8 percent from the last half of 2009.

SMS-capable devices increased to 243.7 million as of June 2010, which is up from 235.3 million in June 2009. There were more than 243.5 million Internet-capable devices during this survey period, which was an increase of more than 6.4 million since June 2009.

Nor are carriers cutting back on their investments. The study reveals that despite tough economic times, the industry continued to invest heavily in wireless infrastructure. Starting in July 2009, carriers spent $21.6 billion in capital expenditures in the past year for a cumulative total of $295.2 billion since CTIA began tracking the data in 1985.