KUALA LUMPUR, April 6  ― The world rose to more bad news today in the hunt for MH370, as last night’s searches, buoyed by promising news of electronic pulse signals emitted from somewhere below the Indian Ocean's surface, still returned with no sign of the aircraft.

In a statement here, Australia’s Joint Agency Coordinating Centre (JACC) said the pulses picked up yesterday by the Chinese vessel Haixun 01, still “cannot be verified at this point in time.”

A day’s worth of battery life is said to be left on MH370’s black boxes, and if at all the pulses had come from the aircraft's recorders, they will likely fade by tomorrow.

Experts have weighed in with positive opinions on the likelihood that it was indeed MH370’s black boxes that were calling for attention but families of those aboard have so far chosen to treat the news cautiously.

Too many false leads have turned up in the massive search for the Boeing 777 jetliner over the past four weeks.

In UK’s The Independent, air safety investigator Phil Giles was quoted saying the signals were promising.

“That's not going to be a whale or a porpoise or a squid or anything like that. It's got to be a mechanical device," the former investigator with UK's Air Accidents Investigation Branch (AAIB) was quoted saying.

“If that [report] is kosher, then it's probably coming from a pinger on a black box. I would think that it's very unlikely that somebody has dumped another black box down there less than a month ago in the Indian Ocean.

“The chances are pretty good that it's from MH370,” he added.

In the same article, aviation expert Chris Yates also agreed that the reported sounds “positive.”

“On the face of it, it's good news, but we have to wait and see,” he was quoted saying.

The signal reportedly picked up was 37.5 kHz, which is consistent with the beacon frequency of an aircraft's cockpit voice recorder and flight data recorder - the two crucial black boxes.

According to pinger manufacturer Dukane Seacom president Anish Patel in a CNN news report, the frequency is used in the recorder “to give that standout quality that does not get interfered with by the background noise that readily occurs in the ocean.”

But Patel reportedly said it was curious why only one signal had been detected when the aircraft has two recorders with such pingers or beacons. These two are located next to each other near the tail of the plane.

Today marks the 29th day since flight MH370 went missing on March 8. The Boeing 777 aircraft carrying 239 people left Malaysian shores at 12.41am that morning and disappeared under an hour later, leaving little clues in its track to help investigators track where it went and why.

Searches in the southern Indian Ocean off Australia’s coast resumed this morning with 10 military planes, two civil planes and 13 ships.

According to the JACC, the Australian Maritime Safety Authority (AMSA) planned three separate searches for today about 2,000 kilometres northwest of Perth, which total some 216,000 square kilometres.

Weather in the search area is reportedly expected to be good, with a cloud base of 2,500 feet and visibility greater than 10 kilometres.

“The Australian Transport Safety Bureau continues to refine the area where the aircraft entered the water based on continuing ground-breaking and multi-disciplinary technical analysis of satellite communication and aircraft performance, passed from the international air crash investigative team comprising analysts from Malaysia, the United States, the UK, China and Australia,” JACC said.